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STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

A.  M.  SHELTON.  Director 

DIVISION  OF  THE 
STATE  GEOLOGICAL  SURVEY 

M.  M.  LEIGHTON,  Chief 

BULLETIN  NO.  53 


GEOLOGY  AND  ECONOMIC  RESOURCES  OF  THE 
ST.  PETER  SANDSTONE  OF  ILLINOIS 


BY 
J.  E.  LAMAR 


PRINTED  BY  AUTHORITY  OF  THE  STATE  OF  ILLINOIS 


URBANA,  ILLINOIS 
1927 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

A.  M.  SHELTON,  Director 

DIVISION  OF  THE 
STATE  GEOLOGICAL  SURVEY 

M.  M.  LEIGHTON,  Chief 

BULLETIN  NO.  53 


GEOLOGY  AND  ECONOMIC  RESOURCES  OF  THE 
ST.  PETER  SANDSTONE  OF  ILLINOIS 


BY 

J.  E.  LAMAR 


PRINTED  BY  AUTHORITY  OF  THE  STATE  OF  ILLINOIS 


URBANA,  ILLINOIS 
1928 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

A.  M.  SHELTON,  Director 

DIVISION  OF  THE 
STATE  GEOLOGICAL  SURVEY 

M.  M.  LEIGHTON,  Chief 


Committee  of  the  Board  of  Natural  Resources 
and  Conservation 

A.   M.   Shelton,  Chairman 

Director  of  Registration  and  Education 

Charles  M.  Thompson 

Representing  the  President  of  the  Uni- 
versity of  Illinois 

Edson  S.  Bastin 
Geologist 


Jeffersons  Printing  &  Stationery  Co. 
Springfield,  Illinois 


CONTENTS 

PAGE 

Chapter  I — Introduction 11 

General   statement    11 

Use  of  terms  "sand"   and   "sandstone" 12 

Purpose  of  report 12 

Acknowledgments 13 

Chapter  II — The  geology  of  the  St.  Peter  sandstone 14 

Name  , 14 

Distribution    14 

Lithology 18 

General   lithologic   character 18 

The  lithology  of  the  basal  St.  Peter  sediments  and  associated  beds 19 

The  lithology  of  the  upper  portion  of  the  St.  Peter  and  associated  beds.  ...  22 

Thickness 24 

Stratigraphic  relations 25 

Structure 25 

Origin  of  the  St.  Peter  sandstone 26 

Geologic  history   29 

Chapter    III — Special    lithologic,    structural,    and    compositional    features    of    the    St. 

Peter   sandstone 32 

Introduction , 32 

Structural  features 32 

Bedding    32 

Cross-bedding   .  .  . • 32 

Ripple   marks    33 

Honeycomb  weathering 35 

Worm  borings    36 

Dessication  or   sun  cracks 36 

Compositional  features    37 

Carbonaceous  bands    37 

Clay  pockets    37 

Interstitial   organic  material 37 

"Magnesia"  beds    38 

Siliceous  joint  fillings 39 

Features  of  the  sand  grains 40 

Size 40 

Shape 44 

Frosting 46 

Pitting    47 

Pits  in  frosted  grains 47 

Pits  in  grains  with  additions  of  secondary  silica 49 

Secondary  enlargement 49 

Number  of  grains 49 

Limestone  and  dolomite  in  the  St.  Peter  sandstone 50 


Chapter   III — concluded  page 

Clay  in  the  St.  Peter  sandstone ,  .  51 

Character    51 

Occurrence 51 

Distribution  52 

Origin    52 

Iron  in  the  St.  Peter  sandstone 54 

Occurrence 54 

Origin   56 

Source  and  mode  of    accumulation . 57 

Heavy  minerals  in  the  St.  Peter  sandstone 59 

Chapter  IV — The  quarrying  and  preparation  of  St.  Peter  sand 63 

Introduction 63 

Washed   sand 63 

General   statement 63 

Types  of  quarries 63 

Overburden    and   its    removal . 65 

Blasting 66 

Hydraulic  quarrying   67 

Elevating  the   sand   from  the   quarry 71 

Preliminary  screening   72 

Washing  the  sand 72 

Draining  the  sand 73 

Drying  the  sand 74 

Screening  the   sand 74 

Shipping  the   sand , 74 

The  manufacture  of  special  sands  or  sand  products 74 

Washed  and  drained  sand . 74 

Standard  Ottawa  sand 75 

Ground   sand   or   silica 75 

Producers  of  washed  sand 76 

Crude  sand   84 

General  statement 84 

Producers  of  crude  silica  sand 85 

Grades  of  washed  and  crude  sand  produced 96 

Washed   sand 96 

Mine-run  sand    97 

Washed  and  drained  sand 97 

Sand-blast  sand    97 

Glass   sand    97 

Banding  sand    97 

Miscellaneous    97 

Ground   silica 97 

Crude  sand 98 

Chapter  V — The  uses  of  sand  and  of  the  St.  Peter  sand 99 

Ground  sand  as  an  abrasive 101 

Sand   as  an   absorbent 101 

Agricultural  sands    101 

Sand   for   annealing 101 

Ground   sand   for   asbestos   shingles 101 

Sand   for  asphalt  pavements 101 

Sheet    asphalt    pavements 101 


Chapter  V— continued  page 

Asphaltic  concrete  pavements 103 

Asphalt  block   pavements 104 

Sand   for   asphaltic  flooring 104 

Backing  sand    .........  ^  ..  . .    104 

Sand  as  a  ballast  for  ships 104 

Banding  sand 104 

Sand    bedding   for    stock    cars 105 

Bird    grit 105 

Brass    sand     . 105 

Sand  for  clay  brick 105 

Sand   for   brick   molding 105 

Sand  for  silica  brick . 106 

Sand  for  sand-lime  brick 106 

Brick    pavements 107 

General    statement 107 

Cement  concrete   base 107 

Bedding  course 107 

Sand 107 

Sand-cement 107 

Joint  filler . 108 

Sand 108 

Cement   grout 108 

Bitumen 108 

St.  Peter  sand  for  use  in  brick  pavements 108 

Burnishing  sand 108 

Sand  for  the  manufacture  of  carborundum.. 109 

Sand  for  cements 109 

Sand   for    chemical    purposes 109 

Coking   sand    . 110 

Sand    for    concrete 110 

Core   sand    '. Ill 

Sand    for    cuspidors Ill 

Cutting   and    sawing   sand Ill 

Desirable   properties    Ill 

St.  Peter  sand   as  cutting  and   sawing  sand 112 

Sand   for   dental    purposes 112 

Sand   for   dispelling  fog 112 

Sand    for    enameling „ 112 

Engine   sand    113 

Sand    for   erasers 113 

Sand    for    explosives 113 

Facing  sand   and  silica  mold  wash  for  foundry  use 113 

Sand  for  facing  tile   and  brick 114 

Sand  for  making  ferro-silicon  and  other  silicon  alloys 115 

Sand  as  a  fertilizer  filler 115 

Sand    as    a   filler 115 

Sand   for   filling  mines 115 

Filter    sand    115 

Fire  sand    ,  116 

Floor    sand     116 


Chapter  V — continued  page 

Sand   as  a  flux  in  metallurgy 116 

French   sand    116 

Friction  sand   117 

Sand    for    making   fused    silica 117 

Furnace    and   fire   sand 117 

Glass    sand    118 

Technical   classification   of   glasses 118 

Impurities    in   glass    sand 118 

Shape  of  sand  grains 119 

Size   of   sand   grains 119 

Proposed  tentative  specifications  for  silica  sand  for  glass-making 119 

General 119 

Requirements     120 

St.  Peter  sand  as  a  glass  sand 121 

Sand  for  making  glazes 121 

Sand  for  golf  tees,  traps,  hazzards,   and  greens 121 

Grinding   and   polishing   sand 123 

Sand   for   grinding  wheels 123 

Horticultural    sands     . 123 

Hour-glass  sand 124 

Sand  for  use  on  icy  streets   and  walks 124 

Loam     124 

Sand    for    matches 124 

Sand    as    a   moisture    pad 125 

Silica  or  sand  mold  wash 125 

Molding  sand 125 

The  properties  and  testing  of  molding  sands 125 

Specifications  for  common  molding  sand 128 

Specifications  for  steel  molding  sand  and  core  sand 128 

The  St.  Peter  sand  as   a  molding  sand 128 

Mortar   sand 130 

Sand  for  use  in  paint  manufacture r ...  130 

Parting  sand .  . 131 

Placing  sand    131 

Sand  for  plasters 131 

Sand  for  plugging  oil  wells 132 

Polishing   sand 133 

Sand  for  use  in  the  manufacture  of  pottery 133 

Poultry  and  bird  grit 134 

Sand  as  railroad  ballast 134 

Sand  for  railroad  fills 134 

Sand   for  refractory  mortars   and   cements 135 

Sand  for  refractory  ware 135 

Roofing  sand 135 

Saggar  or   placing  sand 136 

Sand  for  sandbags 136 

Sand-blast  sand 136 

Sand   for  sand  baths 137 

Sand-clay  roads    .* 137 

Sand   for   sand    finishing   painted    surfaces 138 


Chapter   V — concluded  page 

Sand   for   sand   finishing   plaster   walls , 138 

Sand  paper  > ; 138 

Sand   for   sand   piles 138 

Sand  for  sand  seals 138 

Sand  for  sand  tables  and  sand  piles 139 

Sawing  sand 139 

Scouring  sand    .  .  . 139 

Setting   sand 139 

Sand  for  sidwalks 139 

Sand  for  making  silicon 139 

Sand   for   use   in   soaps 140 

Sand  for  making  sodium  silicate    (water  glass) 140 

Standard   Ottawa  sand 140 

Sand  for  stone-block  pavements .-...' 140 

Sand  for  stucco .  .  .' 140 

Sand  for  sweeping  compounds .:.... 141 

Sand  in  tar  and  roofing  paper 141 

Sand  for  terrazzo  floors 141 

Sand  for  testing  detonators 141 

Testing  sand :     Standard  Ottawa  sand 141 

Tumbling  sand 141 

Sand  for  making  water  glass 142 

Sand  for  welding 142 

Sand  for  wood-block  pavements 142 

Chapter  VI — Sampling  and  testing  of  St.  Peter  sand 143 

Value  of  tests 143 

Sampling  the   sandstone . 143 

General   statement    143 

Kinds  of  samples 144 

Splitting  the   sample   in   the   quarry 144 

Shipping  the   sample 145 

Splitting  the   sample  in  the   laboratory 145 

Mechanical  analysis  of  samples  and  tables  of  results 146 

Method  of  testing  the  sand 146 

Results  of  mechanical  analyses 148 

Tests  for  angularity 148 

Methods  of  procedure 148 

Results  of  tests 150 

Tests  to  determine  the  number  of  grains  in  a  unit  weight  of  sand 152 

Method   of  procedure 152 

Results  of  tests 152 

Chemical   analyses    1 54 

Modes  of  expressing  texture  from  mechanical    analyses 155 

Effective  size 155 

Uniformity   coefficient 155 

Fineness    155 

Per  cent  of  fineness 156 

Average   fineness    (Scranton   method) 156 

Average  grain  size 157 

Fineness  modulus    157 

The  number  of  grains  as  a  measure  of  fineness 158 


Chapter  VI — concluded  PAGE 

Proposed  classification  of  St.  Peter  sand  on  the  basis  of  fineness  modulus 158 

Graphic  methods  of  representing  sieve   analyses 159 

Chapter  VII — Undeveloped   deposits   of   St.   Peter  sandstone  of  potential   commercial 

value    162 

Introduction    162 

The  rock  terrace  of  Illinois  River  in  the  vicinity  of  Ottawa 162 

Buffalo  rock 163 

The  north  bluff  of  Illinois  River  from  Ottawa  to   Utica 163 

The  Illinois  River  bluff  west  of  Utica 163 

The  south  bluff  of  Illinois  River , 164 

Vermilion  River , 164 

Pecumsaugan  Creek   164 

Clark  Run , 164 

Fox  River 165 

The  Oregon-Dixon  area 165 

Brookville-Harper    area    166 

Calhoun  County 166 

Index 167 


ILLUSTRATIONS 

FIGURE  PAGE 

1.  Graph   showing  the    amounts    and   values   of   the   various   grades   of   St.   Peter 

sand  produced  in  Illinois  in  1925 11 

2.  Map  showing  the  distribution  of  the  St.  Peter  sandstone  in  the  United  States..  15 

3.  Generalized  sketch  of  the  north  bluff  of  Illinois  River  showing  the  position  of 

the  St.  Peter  sandstone  and  the  overlying  and  underlying  beds 16 

4.  Outcrop  of  St.  Peter  sandstone  at  Castle  Rock  in  the  northwest  bank  of  Rock 

River  near  Oregon,  Ogle  County 17 

5.  Cross-bedding  in  the   St.  Peter  sandstone  in  the  quarry  of  the  Wedron   Silica 

Company    33 

6.  Exposure  of  St.  Peter  sandstone  in  the  quarry  of  the  Wedron  Silica  Company.  .  34 

7.  Slab  of  ripple-marked   St.  Peter   sandstone 35 

8.  Worm  borings  in  the  St.  Peter  sandstone 36 

9.  "'Magnesia"  bed  and  cross-bedded  sandstone  in  the  quarry  of  the  United  States 

Silica  Company    38 

10.  Graphs  showing  texture  of  typical  St.  Peter  sand  and  of  "magnesia"  sand.  ...  39 

11.  Eroded  siliceous  veins  in  the   unworked   portion   of  the  quarry  of  the   Ottawa 

Silica  Company    40 

12.  Sieve  analyses  of  sand  from  given  beds  in  four  different  quarries 41 

13.  Sieve  analyses  by  volume  of  sand  from  the  various  beds  of  the  east,  west,  and 

south  faces  of  the  quarry  of  plant  A,  Ottawa  Silica  Company 43 

14.  Sieve  analyses  in  per  cent  by  weight  of  face  samples  from  the  quarry  of  plant 

A,  Ottawa  Silica  Company .  .  .  . 44 

15.  Sieve    analyses   in   per   cent   by   Weight    of   sand    from    exposures    of    St.    Peter 

sandstone  to  show  the  variations  in  the  texture  of  the  sandstone  in  different 

localities    •  45 

16.  St.  Peter  sand  showing  the  character  of  the  surface  and  shape  of  the  grains.  .  46 

17.  Medium-sized  St.  Peter  sand  showing  the  typical  shape  and  surface  of  grains 

of  this   size 47 

18.  Quarry  and  plant  of  the  Wedron  Silica   Company 64 

19.  Quarry  of  plant  B,  Ottawa  Silica  Company 65 

20.  Gasoline  tractor  shovel  and  side  dump  cars  used  for  removing  overburden  at 

the  quarry  of  the  Wedron  Silica  Company 66 

21.  Hydraulic  quarrying  of  the  St.  Peter  sand 67 

22.  Generalized  diagrammatic  flow  sheet  for  washed  St.  Peter  sand 68 

23.  Sand  pump  in  quarry  of  United  States  Silica  Company 69 

24.  Quarry  of  the  Ottawa  Silica  Company 70 

25.  Gathering  sump  in  quarry  of  Ottawa  Silica  Company 70 

26.  Drag-belt   elevator    71 

27.  Draining  bins  of  Ottawa  Silica  Company 73 

28.  Tube  mills  in  plant  of  National  Silica  Company.  .  , 75 

29.  Locations  of  the  St.  Peter  sand  quarries  in  the  Ottawa-Utica  district 77 

30.  Plant  of  the   National    Silica    Company 81 

31.  Quarry   of   the    National    Silica    Company 81 


FIGURE  PAGE 

32.  Flow  sheet  of  plant  of  National  Silica  Company 82 

33.  Circular  washers  in  plant  of  National  Silica  Company 83 

34.  Churn  drill  used  for  making  primary  blast  holes 85 

35.  Drag-line  scraper  bringing  sand  on  to  bar  grizzly 86 

36.  The  No.  2  quarry  of  the  American  Silica  Sand  Company 87 

37.  The  overburden  at  the  quarry  of  the  Benson-Richards  Sand  Company 88 

38.  The  quarry,  and  loading  machinery  of  the  Buffalo  Rock  Silica  Company 90 

39.  End-dump   car   discharging   into    railroad    car 91 

40.  The  quarry  and  plant  of  the  Ottawa  Silica  Molding  Sand  Company 94 

41.  Graph  showing  the  composition  of  the  samples  from  the  quarry  of  the  Ottawa 

Silica  Company  in  per  cent  by  number  of  grains 152 

42.  Graphs  showing  the   analyses  by  number  of  grains  of  bed   samples   from  the 

quarries    of    the    Ottawa    Silica    Company    and    the    Benson-Richards    Sand 

Company    154 

43.  Graphic   methods   of   representing   sieve    analyses 160 


PLATE 

I.     Map  showing  the  distribution  of  the  St.  Peter  sandstone  in  Illinois 14 

II.     Map  showing  the  thickness  of  the  St.  Peter  sandstone  in  Illinois 24 

III.     Structure  contour  map  drawn  on  the  top  of  the  St.  Peter  sandstone  in  Illinois.  .  26 


TABLES 

PAGE 

1.  Chemical  analyses  of  St.  Peter  clays 51 

2.  Iron  in  the   St.  Peter   sandstone 55 

3.  Heavy  mineral  content  of  the  St.  Peter  sandstone 60 

4.  Size  of  heavy  mineral   grains 61 

5.  Standard  gradings  for  sand  for  sheet  asphalt  pavements 102 

6.  Average  grading  of  sands  recently  used  in  sheet  asphalt  pavements 103 

-9.     Tables  showing  specifications  for   silica  sand  for  glass-making 120,  121 

9a.  Constants  for  Tyler  Standard  Screen  Scale  Sieves 147 

10.  Results  of  fineness  tests  of  St.  Peter  and  other  sands  in  per  cent  by  weight.  .  .  148 

11.  Results  of  fineness  tests  of  St.  Peter  sand  in  per  cent  by  number  of  grains.  .  .  .  150 

12.  Results   of   angularity   tests 151 

13.  Results  of  tests  to  determine  the  number  of  grains  in  a  unit  weight  of  sand.  .  153 

14.  Chemical  analyses  of  St.  Peter  sand 154 

15.  The  effective  size  and  uniformity  coefficient  of  St.  Peter  sand  from  quarries  of 

plants    producing    washed    sand 155 


GEOLOGY  AND  ECONOMIC  RESOURCES  OF  THE 
ST.  PETER  SANDSTONE  OF  ILLINOIS 

By  J.  E.  Lamar 


CHAPTER  I— INTRODUCTION 

General  Statement 

The  silica  sand  industry  of  Illinois  is  one  not  only  of  great  state  im- 
portance but  also  of  national  importance.  Illinois  ranks  first  in  the  produc- 
tion and  value  of  glass  sand,  which  it  ships  to  many  parts  of  the  United 
States;  in  1925  over  34  per  cent  of  the  sand  sold  in  the  country  for  the 
manufacture  of  glass  was  produced   from  the  St.   Peter  formation  of  the 


Total  production 
1,905,145  tons 


Grinding  and 
polishing 


Ground  quartz 


$  51,41 1  Grinding  and  polishing 


Fig.  1. 


Graph  showing  the  amounts  and  values  of  the  various  grades  of  St.  Peter 
sand  produced  in  Illinois  in  1925. 


State.  In  the  same  year,  26  per  cent  of  the  country's  production  of  ground 
sand  or  sandstone  came  from  the  St.  Peter  of  Illinois  as  well  as  a  large  per 
cent  (no  actual  figure  is  available)  of  the  steel  molding  sand  produced  in  the 
United  States.  Perhaps  the  most  widely  used  and  known  product  of  Illinois 
silica  sand  industry  is  the  Ottawa  Standard  Testing  sand.  Although  the 
actual  tonnage  of  this  type  of  sand  produced  is  small,  it  is  standard  through- 
out the  United  States  and  in  some  foreign  countries  for  testing  cements  and 
for  other  testing  purposes  when  a  very  uniform,  even  textured  sand  is  de- 
sired. The  division  according  to  uses  of  the  total  production  of  St.  Peter 
sand  in  Illinois  for  1925  is  shown  in  figure  1. 

11 


12  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

Since  early  in  the  nineteenth  century  and  possibly  before,  the  St.  Peter 
sandstone  of  Illinois  has  been  known  as  a  high  silica  sand.  Its  earliest  known 
uses  as  a  high  silica  sand  were  for  molding  and  for  bottle  and  window  glass. 
With  the  demand  of  late  years  for  sands  of  a  given  sieve  analysis  and  purity, 
the  industry  has  developed  into  one  of  the  important  mineral  industries  of 
Illinois.  In  pre-railroad  days,  commercial  development  of  the  sandstone  in 
the  bluffs  and  rock  terraces  of  Illinois  and  Fox  rivers  and  along  the  Illinois 
and  Michigan  Canal  in  the  vicinity  of  Ottawa  and  Utica  was  feasible  because 
of  favorable  quarrying  conditions  and  easily  accessible  water  transportation. 
In  the  present  era  of  railroad  transportation,  the  Chicago,  Rock  Island  and 
Pacific  Railway  and  the  Chicago,  Burlington  and  Quincy  Railroad,  following 
the  valleys  of  the  same  streams  respectively,  afford  modern  shipping  facilities 
to  the  St.  Peter  sand  industry. 

The  future  of  the  Illinois  silica  sand  industry  has  its  problems  and  its 
encouragements.  The  producers  of  crude  sand  are  generally  being  forced  to 
more  systematic  and  up-to-date  methods  of  stripping,  as  the  quarries  are 
worked  back  into  territory  with  thicker  overburden.  The  prevalent  low  price 
for  crude  sand  has  necessitated  more  economical  and  modern  loading  meth- 
ods. Quantity  production  essentially  has  made  continued  operation  possible. 
The  further  success  of  the  silica  sand  industry  as  a  whole  is  probably  depend- 
ent on  unification  of  effort,  and  cooperation  towards  the  elimination  of 
wasteful  competition.  Without  doubt  the  completion  of  the  Lakes  to  Gulf 
deep  waterway  will  stimulate  greater  production  because  of  anticipated  lower 
freight  rates  on  bulk  shipments  of  sand  to  Great  Lakes  and  Mississippi 
River  markets. 

Use  of  Terms  "Sand"  and  "Sandstone" 

There  is  no  little  confusion  in  the  literature  on  the  St.  Peter  formation 
regarding  the  use  of  the  terms  "sand"  and  "sandstone."  It  has  seemed  advis- 
able, therefore,  to  define  these  terms  as  used  in  this  report.  By  St.  Peter 
sand  is  meant  the  unconsolidated  product  resulting  from  the  disintegration, 
either  natural  or  artificial,  of  the  St.  Peter  sandstone.  The  term  sandstone  is, 
used  to  describe  the  formation  as  it  occurs  in  the  natural,  undisintegrated 
.ctate. 

Purpose  of  Report 

In  view  of  the  local  and  national  importance  of  the  St.  Peter  sandstone 
of  Illinois,  the  study  of  the  formation  was  undertaken  in  the  summer  of  1925 
to  obtain  detailed  data  concerning  it  and  to  further  a  better  understanding  of 
the  character  and  details  of  the  sandstone  and  the  industry  dependent  upon 
it,  both  from  the  economic  and  from  the  scientific  standpoint. 


INTRODUCTION  13 

Acknowledgments 

In  the  field  and  office  work  incident  to  this  report  the  cooperation  of  the 
St.  Peter  sandstone  operators  has  always  been  most  willing  and  helpful ;  the 
author  wishes  to  express  his  sincere  appreciation  to  these  men.  Acknowledg- 
ment is  made  of  the  valuable  services  of  Mr.  H.  G.  Martin  who  assisted  in 
the  field  work  and  of  Mr.  C.  R.  Clark  who  helped  in  testing  the  sand  samples. 
The  geological  reports  on  the  Oregon,  Dixon,  Ottawa-Marseilles,  and  La 
Salle-Hennepin  quadrangles  by  Messrs.  A.  Bevan,  R.  S.  Knappen,  L.  W. 
Currier,  and  G.  H.  Cady  respectively,  have  been  freely  referred  to  during  the 
preparation  of  this  report  and  acknowledgment  is  made  of  the  valuable  infor- 
mation obtained  from  the  bulletins  and  unpublished  manuscripts.  The  con- 
structive criticism  of  the  manuscript  by  Professor  C.  W.  Parmelee  of  the 
Department  of  Ceramic  Engineering  of  the  University  of  Illinois,  is  also 
gratefully  acknowledged.  To  Dr.  M.  M.  Leighton,  Chief  of  the  Illinois  Geo- 
logical Survey,  the  author  wishes  to  express  thanks  for  his  valuable  criti- 
cisms of  the  work  and  generous  administration  of  affairs ,  pertaining  to  the 
investigation. 


CHAPTER  II— THE  GEOLOGY  OF  THE  ST.  PETER  SANDSTONE 

Name 

The  St.  Peter  sandstone  was  named  by  Owen1  in  1847  from  exposures 
near  St.  Paul,  Minnesota,  along  the  present  Minnesota  River  formerly  known 
as  St.  Peter  River.2 

Distribution 

The  distribution  of  the  outcrops  of  the  St.  Peter  sandstone  in  the  United 
States  and  the  approximate  area  underlain  by  this  formation  are  indicated  in 
figure  2.  It  is  to  be  noted  that  the  sandstone  is  found  principally  in  the  area 
drained  by  the  Mississippi  and  its  tributaries. 

In  many  places  throughout  Illinois,  the  St.  Peter  is  penetrated  by  deep 
wells  and  doubtless  underlies  all  of  the  State  with  the  exception  of  local  areas 
where  it  has  been  removed  by  erosion.  However,  the  sandstone  outcrops  in 
comparatively  few  places  which  may  be  grouped  into  four  principal  areas 
(PI.  I)  ;  these  are,  in  the  order  of  importance,  the  Ottawa-Utica  area,  includ- 
ing the  outcrops  along  Illinois  River  west  of  Ottawa  for  about  8  miles  and 
on  Fox  River  from  Ottawa  north  to  Millington  about  25  miles,  the  Oregon- 
Dixon  area,  the  Brookville-Harper  area,  and  the  Calhoun  County  area. 

In  the  Ottawa-Utica  area  the  sandstone  is  exposed  in  rock  terraces  in 
Illinois  River  Valley  for  a  distance  of  about  3  miles  from  Ottawa  to  Twin 
Bluffs,  in  the  vicinity  of  Ottawa,,  and  north  from  the  city  in  the  rock  ter- 
races along  Fox  River.  Locally  the  sandstone  forms  a  bluff  in  the  vicinity  of 
Wedron  on  the  Fox.  The  outcrops  are  in  general  relatively  free  from  iron 
compounds  and  are  part  of  the  upper  portion  of  the  St.  Peter  formation.  The 
covering  on  the  rock  terraces  is  thin — in  most  places  its  thickness  varies  from 
6  inches  to  about  10  feet — and  consists  of  river  alluvium,  glacial  gravel  and 
glacial  drift.  Locally  a  thin  capping  of  Platteville-Galena  limestone  is 
present.  Because  the  sandstone  is  free  from  iron  and  because  the  overburden 
is  relatively  thin,  these  rock  terraces  are  the  sites  of  most  of  the  quarries 
producing  washed  sand. 

From  Twin  Bluffs  west  to  Utica,  the  St.  Peter  rises  in  the  north  bluff 
of  Illinois  River.  For  about  4  miles  west  from  Twin  Bluffs,  the  bluff  is 
capped  with  clay  and  coal  of  Pennsylvanian  age.  (See  fig.  3.)  This  is  the 
area  in  which  the  yellowest  sand  is  found.  From  the  western  limit  of  the 
Pennsylvanian  beds  west  to  Utica,  a  distance  of  about  2  miles,  the  sandstone 


lOwen,    I).    1).,   Sen.    Uxec.   Doc,   No.    2.   30th   Cong.,   1st   sess.,   p.    169,   1847. 
2Knappen,   R,    S.,   Geology  and   mineral   resources   of   the   Dixon   quadrangle:     Illinois 
State  <;.•<,!.   Survey   Bull.   49,  p.   48,   1926. 

14 


ois  State  Geological  Survey 


Bulletin  No.  53,  Plate  I 


Outcrop  of  St.   Peter  sandstone 


Area  where  St.  Peter  sandstone  Imme- 
diately underlies  the  surficial  ma- 
terials or  is  known  to  be  present  at 
a  shallow  depth. 


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DISTRIBUTION 


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THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


is  somewhat  less  yellow.  Glacial  drift  caps  the  sandstone.  West  of  Utica 
the  sandstone  is  not  present  in  the  river  bluff  along  the  crest  of  the  La  Salle 
anticline  for  a  distance  of  about  1*4  miles.  In  the  vicinity  of  Pecumsaugan 
Creek,  however,  the  sandstone  appears  again  in  the  upper  part  of  the  bluff 
and  at  Split  Rock  dips  sharply  to  the  west  beneath  Pennsylvanian  beds.  Out- 
crops of  the  St.  Peter  are  found  in  most  of  the  tributary  valleys  in  the  north 
bluff  of  Illinois  River;  also  at  intervals  along  Little  Vermilion  River  from 
Troy  Grove  south  to  sec.  27,  T.  34  N.,  R.  1  E. ;  along  the  lower  4  miles  of 
Tomahawk  Creek  and  along  the  tributaries  of  Little  Vermilion  River  in  sec. 
2,  T.  33  N.,  R.  1  E. 

In  the  south  bank  of  Illinois  River  the  St.  Peter  forms  bluffs  and  out- 
crops in  the  valleys  incident  to  the  bluffs  from  Ottawa  to  Little  Rock  about 
2]/2  miles  southwest  of  Utica.  The  overlying  formations  are  principally 
Pennsylvanian  beds  though  locally,  as  at  the  edge  of  the  bluff  in  Starved 
Rock  State  Park  and  near  Little  Rock,  the  sandstone  is  bare  or  is  covered 
with  a  thin  mantle  of  soil  or  glacial  till. 


ELEVATION 


Pennsylvanian         Platteville  St.  Peter  Shakopee 

clay,   shale,  Galena  sandstone  dolomite 

and  coal  limestone 


Fig.  3.     Generalized  sketch  of  the  north  bluff  of  Illinois  River  showing  the  position 
of  the  St.  Peter  sandstone  and  the  overlying  and  underlying  beds. 


Buffalo  Rock,  standing  alone  in  the  flood-plain  of  the  Illinois,  is  an 
erosion  remnant  of  St.  Peter  sandstone  capped  by  Pennsylvanian  beds.  It 
was  probably  once  a  part  of  the  north  bluff  of  the  river.  The  sandstone  is 
principally  the  yellow  type  sold  for  steel  molding. 

Another  limited  outcrop  of  St.  Peter  occurs  at  Deer  Park  about  a  mile 
and  a  half  east  of  Oglesby,  where  the  sandstone  forms  cliffs  and  canyons. 

About  a  mile  northeast  of  Millington  in  Kendall  County,  erosion  of  a 
low  arch  in  the  rock  strata  has  exposed  the  St.  Peter  in  the  banks  of  Fox 
River  at  intervals  for  a  distance  of  one  or  two  miles.  The  quarry  of  the 
Ballou  White  Sand  Company  is  located  in  this  outcrop.  The  sand  is  princi- 
pally white  or  light  yellow. 

In  the  Oregon-Dixon  area  in  Lee  and  Ogle  counties  the  St.  Peter  forms 
the  steep  slopes  and  bluffs  of  the  northwest  valley  wall  of  Rock  River.  In 
the  region  immediately  south  of  Oregon  the  bluff  is  very  precipitous.  Castle 
Rock  is  an  isolated  rock  hill  composed  of  St.  Peter  sandstone  (fig.  4).    Aside 


DISTRIBUTION 


17 


from  its  scenic  beauty,  Castle  Rock  is  of  interest  because  it  shows  the  bedded 
and  locally  cross-bedded  character  of  the  St.  Peter  and  is  a  typical  example 
of  the  better  exposures.  Away  from  the  river,  the  sandstone  outcrops  along- 
many  creeks  and  underlies  a  broad  band  of  country  which  is  about  2  miles 
wide  in  the  vicinity  of  Oregon.  It  is  in  this  area  of  outcrop  that  the  quarry 
of  the  National  Silica  Company  is  located. 

On  the  southeast  side  of  Rock  River  the  sandstone  outcrops  from  Days- 
ville  south  of  Franklin  Creek  but  forms  conspicuous  bluffs  only  in  sees.  29 
and  31,  T.  23  N.,  R.  10  E.  The  sandstone  underlies  the  region  between  Clear 
and  Franklin  creeks  and  also  outcrops  in  the  southwest  bank  of   Franklin 


Fig.  4.     Outcrop   of  St.  Peter  sandstone   at   Castle   Rock  in   the   northwest  bank   of 
Rock  River  near   Oregon,   Ogle   County. 

Creek  to  sec.  2,  T.  21  N.,  R.  10  E.  There  are  also  scattered  outcrops  south 
of  Grand  Detour,  in  the  vicinity  of  Franklin  Grove,  and  along  Pine  Creek  in 
sees.  15,  22,  23,  and  27,  T.  23  N.,  R.  9  E. 

Northwest  of  Oregon  about  three  quarters  of  a  mile,  the  St.  Peter  forms 
the  upper  slopes  of  a  prominent  ridge.  There  are  also  scattered  outcrops  in 
the  vicinity  and  in  sees.  5,  6,  and  8,  T.  23  N.,  R.  11  E.  In  the  outcrops  of 
the  Oregon-Dixon  region  the  St.  Peter  is  overlain  either  by  glacial  drift  alone 
or  by  the  Glenwoocl  and  Platteville  formations  together  with  glacial  drift. 

North  of  Leaf  River  in  the  S.  y2  sec.  25,  the  SE.  y±  sec.  23  and  the 
N.  Y\  sec.  24,  T.  25  N.,  R.  9  E.,  there  are  a  few  outcrops  of  St.  Peter  sand- 
stone overlain  by  Platteville-Galena  limestone. 

In  northwest  Ogle  County  between  Harper  and  Brookville  the  St.  Peter 
outcrops  along  some  of  the  streams  and  in  some  hill  tops.  The  sandstone  is 
in  general  yellow,  and  is  commonly  overlain  by  glacial  drift. 


18  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

A  small  outcrop  of  upper  St.  Peter  occurs  in  Winnebago  County  north- 
west of  Shirland  in  sec.  32,  T.  29  N.,  R.  11  R,  along  Sugar  River.  In  the 
center  of  the  NE.  V\  of  the  section,  8  or  10  feet  of  green  sand  is  exposed 
.  overlain  by  Platteville  limestone.  About  half  a  mile  southwest  in  the  opposite 
bank  of  the  river  about  15  feet  of  medium-bedded  calcareous  sandstone, 
probably  St.  Peter,  is  exposed. 

In  Calhoun  County  the  St.  Peter  forms  a  precipitous  bluff  along  Missis- 
sippi River  from  Dogtown  Landing  in  the  SW.  corner  sec.  29,  T.  12  S., 
R.  2  W.,  north  for  about  a  mile.  The  outcrop  is  the  result  of  deformation 
of  the  rock  strata  along  the  Cap-au-Gres  fault  which  extends  E.  5°  S.  through 
Dogtown  Landing.  The  St.  Peter  outcrops  on  the  upthrow,  or  north  side  of 
the  fault.  In  general  the  sandstone  is  more  firmly  cemented  than  the  St. 
Peter  in  the  Ottawa  district  and  contains  nodules  and  bands  of  calcarerous 
sandstone,  particularly  in  the  upper  portion  of  the  exposure.  It  seems  likely 
that  this  calcarerous  material  has  been  introduced  into  the  sandstone  by  water 
percolating  downward  from  the  overlying  limestones.  The  sandstone  contains 
numerous  concretion-like  structures  of  sand  which  have  a  maximum  diameter 
of  eight  inches  and  resemble  large  oolite  grains.  Some  have  five  rings  of 
green  and  pink  mottled  sand.  Locally  the  sand  contains  a  considerable  amount 
of  iron  oxide,  which  occurs  principally  as  bands  roughly  paralleling  the  bed- 
ding. The  sand  in  the  weathered  portions  of  the  outcrop  commonly  show  sec- 
ondary additions  to  the  grains.     Numerous  small  ripple  marks  are  present. 

Lithology 
general  lithologic  character 

Perhaps  the  outsanding  lithologic  features  of  the  St.  Peter,  and  the  ones 
for  which  it  is  best  known  are  the  purity,  homogeneity,  roundness  of  the  sand 
grains,  and  saccharoidal  character  of  the  sandstone.  In  Illinois  at  least  the 
rounded  sand  grains  are  principally  the  larger  grains.  It  is  of  interest  that 
the  rounding  of  the  grains  of  the  older,  New  Richmond  sandstone,  outcrop- 
ping along  Franklin  Creek  near  the  town  of  Franklin  Grove  in  Lee  County, 
is  not  notably  different  from  that  of  the  St.  Peter  sand  grains;  yet  the 
younger  sandstone  is  probably  more  persistent  and  extensive  laterally,  and  is 
commonly  more  easily  identifiable  because  it  is  the  first  sandstone  of  any 
consequence  with  rounded  grains  encountered  in  wells  drilled  in  Illinois. 

In  general  the  Illinois  St.  Peter  is  a  thick-bedded  deposit  but  the  bedding 
is  not  as  distinct  as  in  other  sandstones  because  of  the  homogeneity  and 
purity  of  the  formation. 

Despite  its  loosely  cemented  character,  the  St.  Peter  withstands  the 
effects  of  weathering  well  in  natural  exposures.  Where  it  is  not  subject  to 
rapid  erosion,  it  is  commonly  brown  and  is  case  hardened  to  such  an  extent 
thai   it  is  sometimes  difficult  to  break  into  the  unweathered  portion  with  a 


LITHOLOGIC    CHARACTER  19 

hammer.  This  case  hardening  seems  to  have  developed  most  in  places  where 
the  sandstone  is  generally  moist.  Where  the  sandstone  is  subject  to  severe 
weathering  it  is  usually  locally  soft  and  loose.  The  color  of  the  sandstone 
depends  principally  on  its  iron  content.  Many  exposures  are  banded  hori- 
zontally with  yellow  beds  of  iron-stained  sand  and  have  also  vertical  or  nearly 
vertical,  ramifying,  vein-like  zones  colored  by  yellow  iron  oxides.  In  other 
places  where  the  iron  content  is  lower  the  sand  is  buff,  gray  or  white. 

THE    LITHOLOGY    OF    THE    BASAL    ST.    PETER    SEDIMENTS    AND    ASSOCIATED    BEDS 

A  study  of  churn-drill  records,  largely  without  samples,  indicates  that 
the  basal  St.  Peter  sediments  deposited  on  the  irregular  surface  of  the  Prairie 
du  Chien  series,  are  varied,  and  that  the  depth  of  the  basins  of  sedimentation 
has  had  no  striking  effect  on  the  type  of  sediments  deposited  in  them.  In 
other  words,  the  basal  St.  Peter  sediments  do  not  possess  consistent  charac- 
teristics typical  of,  or  apparently  related  to,  their  topographic  position  on  the 
irregular  surface  of  the  Prairie  du  Chien. 

The  most  common  rock  reported  immediately  below  the  St.  Peter  is  the 
Shakopee  limestone  or  dolomite  of  the  Prairie  du  Chien  series.  Some  alter- 
nations of  comparatively  thin  beds  of  dolomite  or  limestone  and  sandstone  or 
sandy  dolomite  are  reported.  It  is  probable  that  these  beds  also  belong  to  the 
Shakopee,  rather  than  to  the  St.  Peter,  as  is  the  case  in  the  Utica-La  Salle 
region  where  the  exposed  Shakopee  contains  beds  of  calcareous  or  dolomitic 
sandstone  which  might  readily  be  reported  in  drill  records  as  sandstone  or 
sandy  dolomite  or  limestone.  Cady3  gives  the  following  section  of  the  Shak- 
opee compiled  from  well  records  in  the  La  Salle  Region : 

Section  of  Shakopee  formation  in  La  Salle  area  Thickness 

Feet 

Dolomite,  light  brownish  gray;  shale,  gray 12 

Sandstone,  colorless,  coarse 4 

Dolomite,  light  brown;  shale;  limestone 38 

Sandstone   _ 5 

Dolomite,  gray,  semi-crystalline 4 

Dolomite,  gray,  slightly  calcareous 25 

Dolomite,   brownish   8 

Dolomite,    white,    calcareous 37 

Dolomite,  white;   shale,   gray;   sandstone 5 

Dolomite,  white,  calcareous,  flinty 6 

Dolomite,    white,    calcareous 24 

Dolomite,   brown   to   buff 18 

Dolomite   and  sandstone 4 

190 

The  sand  noted  in  the  Shakopee  at  the  outcrop  was  rounded  and  re- 
sembled greatly  the  sand  from  the  St.  Peter  or  New  Richmond  sandstones. 
The  formation  also  contains  locally  beds  of  siliceous  oolite,  which  might  be 
called  sand  by  those  unacquainted  with  oolite. 

3Cady,   G.   H.,   Geology  and   mineral   resources   of  the   Hennepin   and   La   Salle   quad- 
rangles :     Illinois   State  Geol.    Survey  Bull.    37,   p.   32,   1919. 


20  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

In  numerous  well  records  shale  is  reported  between  the  beds  which  are 
strictly  Shakopee  and  those  which  are  definitely  St.  Peter,  but  it  was  not  seen 
in  outcrop.  It  is  commonly  reported  as  red,  shaly  marl,  or  red  marl  shale,  or 
as  green,  blue  or  gray  shale.  In  the  Joliet  region  a  maximum  of  60  feet  of 
red  shale  is  recorded,  also  25  feet  of  micaceous  green  shale,  and  15  feet  of 
blue  clay.  At  Dwight  in  Livingston  County  the  St.  Peter  is  underlain  by  10 
feet  of  green  shale ;  at  Zion  City  in  Lake  County  by  20  feet  of  red  shale 
marl ;  at  North  Chicago  in  the  same  county  by  50  feet  of  shale,  gray,  with 
red  spots  in  the  upper  portion  and  red  with  green  spots  and  mottled  chert 
pebbles  in  the  lower  portion;  and  at  Area  (Mundelein)  in  Lake  County  green 
shale  is  reported  below  the  sandstone.  In  McHenry  County  three  wells  on 
one  farm  near  Harvard  record  62,  43,  and  69  feet  of  red  shale  or  marl.  In 
Jo  Daviess  County  at  Galena  red  and  purple  shale  are  reported ;  at  Kamps- 
ville,  Calhoun  County,  7}/£  feet  of  blue  shale ;  at  Mt.  Carmel  cemetery  in 
Cook  County  10  feet  of  green  shale;  at  Rock  Island  in  Rock  Island  County 
5  to  30  feet  of  red  shale ;   at  Amboy  in  Lee  County  10  feet  of  shale. 

The  red  shale  is  doubtless  a  consolidated  clay  which  originated  as  a  re- 
siduum from  the  solution  of  the  Shakopee  dolomite  at  some  time  during 
the  interval  between  the  deposition  of  the  Shakopee  and  the  beginning  of  St. 
Peter  deposition.  It  is  possible  that  the  green  and  blue  shales  have  orginated 
in  the  same  fashion  from  limestone  containing  a  smaller  amount  of  iron,  or 
that  the  green  and  blue  colors  are  due  to  a  difference  in  the  chemical  condition 
of  the  iron  in  these  shales  as  compared  with  the  iron  in  the  red  shales. 
Studies  of  the  probable  topographic  occurrence  of  these  different  colored 
clays  on  the  pre-St.  Peter  sub-surface  land  mass  do  not  indicate  any  unique 
topographic  position  for  any  specific  variety. 

Some  of  these  shales  lying  beneath  the  St.  Peter  proper  are  reported  to 
contain  chert  fragments  which  are  doubtless  residual  from  a  cherty  limestone. 

The  question  arises  whether  these  residual  clays  should  be  included  with 
the  St.  Peter  or  the  Shakopee.  Inasmuch  as  they  represent  rock  materials 
accumulated  neither  during  Shakopee  nor  during  St.  Peter  time  it  would 
seem  that  they  should  not  be  included  with  either  of  the  twTo  formations  but 
rather  be  considered  as  a  separate  formation.  However,  as  the  St.  Peter  sea 
encroached  upon  the  region  of  these  residual  clays  sufficient  material  of  St. 
Peter  age  was  mixed  with  the  upper  portion  of  the  clays  so  that  in  general 
a  sharp  upper  contact  is  lacking,  and  the  shales  have  therefore  commonly 
been  included  with  the  St.  Peter. 

One  of  the  frequently  reported  basal  St.  Peter  sediments  is  sandstone 
with  chert  pebbles.  Although  this  type  of  chert  conglomerate  is  known  in 
many  different  parts  of  the  State,  it  seems  best  developed  in  Cook  and  Lake 
counties  where  30  feet  of  sandstone  with  pebbles  of  chert  is  commonly  re- 
ported.    Tn  sonic  places  green  shale  is  intercalated  with  the  conglomerate. 

Chert  conglomerate  was  noted  in  the  base  of  the  St.  Peter  in  outcrop 
only  at  the  center  of  the  E.  Y>  NK.  %  sec.  28,  T.  22  N.,  R.  10  E.    The  ex- 


LITHOLOGIC    CHARACTER  21 

posure  at  this  place  consists  of  about  5  feet  of  green  sandstone  with  a  3-inch 
bed  of  conglomerate  near  the  base.  The  conglomerate  pebbles  consist  princi- 
pally of  chert,  and  their  size  ranges  from  that  of  coarse  sand  to  about  that  of 
a  pea.  One  vein-quartz  pebble  and  a  number  of  pebbles  of  quartzitic  sand- 
stone were  also  noted.  The  pebbles  are  all  rounded,  and  the  pitted  surface  of 
the  chert  indicates  that  it  underwent  a  long  period  of  solution.  Most  of  the 
chert  is  yellow  or  white.  The  matrix  of  the  conglomerate  is  sand  consisting 
of  rounded  grains  of  typical  St.  Peter  character.  On  the  whole  it  is  medium 
or  fine-grained,  but  locally  the  conglomerate  contains  bands  of  coarse  sand. 

In  view  of  the  presence  of  the  vein-quartz  pebble  and  the  rounded  sand- 
stone pebbles,  it  seems  likely  that  there  was  transportation  of  coarse  material 
from  without  the  Illinois  St.  Peter  basin,  since  the  Shakopee  is  not  known  to 
contain  materials  similar  to  the  vein-quartz  and  sandstone  with  the  siliceous 
cement. 

A  very  characteristic  phase  of  the  basal  St.  Peter  in  the  La  Salle  region 
is  oolitic  chert  as  beds  and  in  clay.  In  the  NW.  corner  sec.  35,  T.  34  N., 
R.  1  E.,  a  blue  clay  containing  oolitic  cherts  is  exposed  below  the  common 
white  St.  Peter.  A  bed  of  oolitic  chert  8  feet  thick,  resting  unconformably  on 
argillaceous  limestone,  probably  the  Shakopee,  was  noted  in  the  creek  in  the 
SW.  corner  NE.  Y\  sec.  7,  T.  33  N.,  R.  2  E.  The  cherty  layer  also  included 
some  sandy  and  calcareous  beds.  A  similar  oolitic  chert  was  noted  near 
Oregon  in  Lee  County  in  the  SE.  ]/A  sec.  29,  T.  23  N.,  R.  10  E. 

Cady4  gives  the  following  description  of  the  contact  of  the  Shakopee  and 
St.  Peter  along  Pecumsaugan  Creek: 

Character  of  strata  at  the  base  of  the  St.  Peter  sandstone   and  the  top  of  the  Shakopee 
dolomite  along  Pecumsaugan  Creek 

Formation  and  bed 

St.  Peter  sandstone: 

Sandstone   or  sand 

Clay,  soft,  blue 

Sandstone  with  flints 

Sand,  brown  to  white 

Clay,  flints  and  yellow  sand 

Flints    and    clay,   yellow,   weathered 

Sandstone,   flinty  

Clay,    blue,    oolitic 

Clay,  blue,  fine;   hard   at  base 

Sandstone,  flinty,  white;  oolitic,  interbedded  with  hard 
blue   clay  not   oolitic 

Flint  

Sand,  oolitic,  and  blue  clay;  in  four  alternating  beds 

Limestone,  white;  some  hard  white  to  blue  clay  and  flints... 

Chert   layer,    oolitic 

Clay,  oolitic,  bluish  to  buff;  lenticular,  few  inches 

Shakopee  dolomite: 

Limestone;  surface  irregular;  rock  has  weathered  ap- 
pearance    


Thicfc 

:ness 

Depth 

Feet 

In. 

Feet 

In. 

1 

1     .... 

2 

3     .... 

9 

3 

9 

1 

6 

5 

3 

4 

5 

7 

1 

5 

8 

1 

5 

9 

1 

2 

6 

11 

6 

7 

5 

7 

8     ... 

6 

'8 

6 

.; 

8 

9 

2 

4 

9 

6 

4Cady,   G.   H.,   Geology   and   mineral   resources   of   the   Hennepin   and   La   Salle   quad- 
rangles:    Illinois   State  Geol.   Survey  Bull.   37,   p.   39,    1919. 


22  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

THE  LITHOLOGY   OF   THE   UPPER   PORTION    OF   ST.    PETER  AND   ASSOCIATED    BEDS 

In  most  places  the  St.  Peter  is  overlain  by  the  Platteville  limestone  except 
in  the  Calhoun  County  area  where  the  Joachim  is  present  and  in  the  region 
around  Ottawa  where  a  large  part  of  the  overlying  Platteville  and  any  other 
subsequent  beds  of  pre-Pennsylvanian  age  have  been  eroded  away  and  Penn- 
sylvanian  strata  or  recent  unconsolidated  sediments  rest  directly  on  the  St. 
Peter.  In  general  the  section  at  the  contact  of  the  Pennsylvania!!  beds  and 
the  St.  Peter  in  the  Ottawa-Utica  area  consists  of  1  to  8  feet  of  non-bedded 
clay  resting  immediately  on  the  St.  Peter,  overlain  by  1  to  2  feet  of  coal 
which  in  turn  is  overlain  by  gray  shale.  The  clay  is  commonly  known  as  fire 
clay  and  has  been  sold  as  such.  It  is  a  white,  plastic  clay  containing  numer- 
ous St.  Peter  sand  grains.  Its  contact  with  the  underlying  sandstone  is  not 
sharp  and  is  usually  not  delimitable  within  less  than  6  inches.  In  the  Oregon- 
Dixon  region  a  green  shale  or  green  sandstone  is  present  between  the  St. 
Peter  and  the  Platteville.  This  formation  has  been  correlated5  with  the  Glen- 
wood  shale  of  eastern  Iowa.  The  formation  is  described,  in  the  Dixon  quad- 
rangle, as  consisting  of  2y2  to  7  feet  of  green  shale  locally  sandy,  and  in  the 
Oregon  quadrangle  principally  of  green  sand  with  minor  amounts  of  shale. 

During  the  present  investigation  the  Glenwood  beds  were  noted  at  a 
number  of  places  in  the  Oregon-Dixon  area.  The  green  color  of  the  strata 
is  the  most  persistent  characteristic ;  otherwise  the  lithologic  details  of  the 
formation  vary  considerably.  The  following  section  gives  a  specific  illus- 
tration of  the  character  of  the  Glenwood  in  the  Dixon  quadrangle. 

Section  of  Glenwood  formation  in  the  NE.  %  sec.  23,  T.  23  N.,  R.  9  E. 

Thickness 
Platteville  Ft.         In. 

Limestone,  buff,  in  8-inch  beds;   lower  2  feet  sandy - 12-)- 

Limestone  and  shale,  limestone  nodules  averaging  about  10  inches  in  length 

in   a  gray  clay  matrix 1  6 

Glenwood 

Shale,  chocolate  brown,  gritty,  thin  bedded 2  6 

Shale,    greenish    gray,    irregularly    bedded 6      

Sandstone,   very   argillaceous,   buff,   in   irregular   beds    about   an  inch   thick; 

bas al    bed s    greenish 1      

St.  Peter 

Sandstone    3-j- 

Covered 

In  the  SW.  %  NE.  ]/A  sec.  29,  T.  23  N.,  R.  10  E.,  an  exposure  of  7  feet 
of  Glenwood  contains  interbedded  red  and  green  shales. 

In  the  Brookville-Harper  area  in  Lee  County  the  St.  Peter  is  overlain 
locally  by  5  or  6  feet  of  green  shale.  The  following  section  was  measured 
at  the  center  of  the  west  line  sec.  12,  T.  24  N.,  R.  7  E. 


BBevan,   Arthur,  The  Glenwood  beds  as  a  horizon  marker  at  the  base  of  the  Platte- 
ville   formation:      Illinois   State   Geo!.    Survey   Rept.   of  Investigations    9,    1926. 


LITHOLOGIC   CHARACTER  23 

Section  in  sec.  12,  T.  2+  N.,  R.  7  E. 

Thickness 
Ft.         In. 

7.  Glacial   drift  ■ 1         — 

6.  Shale,  green  - —  10 

5.  Sandstone,  loosely  cemented,  coarse  grained,  stained  brown  by  iron 5 

4.  Covered  3 

3.     Shale,   sandy,  greenish-gray - - 5          — 

2.  Sandstone,  top  irregular,  much  stained  by  iron,  fine  grained,  grades  into 

massive    sandstone    below 6-\~ 

1.  Covered 

In  this  section  beds  3  to  6  inclusive  are  probably  Glenwood  and  bed  2 
St.  Peter. 

Another  outcrop  of  green  Glenwood  sand  was  noted  in  Winnebago 
County  along  Sugar  River,  in  the  NE.  *4  sec.  32,  T.  29  N.,  R.  11  E.,  near 
Shirland,  where  the  following  section  is  exposed : 

Section  in  sec.  32,  T.  29  N.,  R.  11  E. 

Thickness 
Feet 

9.  Sand,    glacial    - - \-\- 

8.  Limestone,    dense,   gray - 10— {— 

7.  Covered    - - 8 

6.  Sandstone,    fine    grained,    firmly    cemented,    quartzitic    in    appearance,    top 

and  bottom  irregular;  grades  into  bed  beneath  it 1 

5.  Sandstone,  yellow,  mottled   with  white 8 

4.      Covered 10 

3.  Sandstone,  green,  locally  contains  discoidal  clay  inclusions 8 

2.  Sandstone,  streaked,  white,  brown  and  red 5 

1.     Covered 

In  the  above  section  bed  8  is  Platteville  limestone,  beds  3  to  6  probably 
Glenwood  and  bed  2  St.  Peter.  An  analysis  of  the  green  sand  of  bed  3 
showed  0.51  per  cent  ferric  oxide. 

As  stated  by  BevanG  the  sandy  Glenwood  consists  principally  of  large  and 
small  grains,  with  medium  size  grains  only  minor  amounts.  A  sieve  analysis 
of  bed  6  of  the  aboye  section  is  given  in  the  table  of  fineness  tests  (Table 

10,  p.  148)  as  sample  No.  63,  and  bears  out  this  statement.  It  is  of  interest 
to  note  that  28.0  per  cent  of  the  sample  was  coarser  than  65  mesh,  and  64.6 
per  cent  finer  than  100  mesh.  These  two  sizes  might  roughly  be  considered 
the  coarse  and  fine  grades.  The  medium  sand  constitutes  then  but  11.3  per 
cent  of  the  sample.  Comparison  of  these  figures  with  other  analyses  of  the 
St.  Peter  shows  that  the  medium  grade  is  below  the  average  amount. 

Throughout  the  State  generally,  the  St.  Peter  is  reported  as  being  di- 
rectly overlain  by  limestone.  There  are  a  number  of  exceptions,  however, 
some  of  which  are : 


fiBevan,   Arthur,   op.   cit.,    p.    8. 


24  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

County  Town  St.  Peter  overlain  by 

Whiteside Sterling 35   feet  shale  and  limestone 

Carroll Savanna 12  feet  blue  shale 

Lee Dixon 50  feet  shale 

DeKalb Sycamore 30  feet  shaly  dolomite 

Genoa +2  feet  sandy  limestone 

Kankakee Kankakee 15   feet  dolomitic    limestone,    locally    sandy    and 

containing  beds  of  green  shale 
McHenry Woodstock 41   feet  sandy  limestone 

The  log  of  a  well  at  %alta,  DeKalb  County,  gives  the  following  sequence 
of  beds :  s- 

Thickness 
Feet 

6.     Limestone    (Platteville-Galena)    210 

5.     Limestone,    sandy 2 

4.     Sandstone    18 

3.     Shale,   sandy  : 2      . 

2.     Shale,  gray  23 

1.     St.  Peter   sandstone 

In  some  places  there  is  a  sharp  line  of  separation  between  the  St.  Peter 
and  Glenwood,  suggestive  of  an  unconformity.  In  others  there  is  a  transition 
zone.  Transition  zones  are  not,  however,  positive  evidence  that  these  forma- 
tions are  conformable  inasmuch  as  the  transition  beds  between  them  may  have 
resulted  from  the  commingling  of  sediments  by  the  advancing  Glenwood  sea 
in  much  the  same  fashion  as  the  sandy  clay  overlying  the  St.  Peter  in  the 
Ottawa-Utica  district  was  formed. 

Thickness 

The  general  thickness  of  the  St.  Peter  is  shown  in  Plate  II  by  means  of 
contours  similar  to  those  on  topographic  maps.  In  making  this  map,  where 
a  number  of  wells  penetrate  the  sandstone  in  a  limited  area,  a  probable  aver- 
age local  thickness  has  been  computed  and  used,  inasmuch  as  the  map  is  not 
of  such  scale  as  to  permit  the  delineation  of  minor  local  details.  In  areas 
where  only  a  single  record  of  the  thickness  of  the  sandstone  is  available  it 
has  not  been  possible  to  determine  the  local  thickness  or  to  evaluate  the  data 
so  carefully. 

An  unusual  instance  of  striking  local  variations  in  thickness  is  found  at 
Joliet  where  wells  record  from  120  to  500  feet  of  St.  Peter.  A  study  of  well 
logs  throughout  the  State  suggests,  however,  that  100  feet  is  the  maximum 
common  local  variation  in  thickness. 

Inasmuch  as  the  upper  surface  of  the  St.  Peter  is  subeven,  it  is  apparent 
that  the  variations  in  thickness  of  the  formation  are  accommodated  for  the 
most  part  in  the  beds  underlying  the  sandstone,  namely  the  Prairie  du  Chien 
scries.  The  areas  of  thick  sandstone  shown  in  Plate  II,  therefore,  indicate  in 
a  genera]  way  the  depressions  in  the  surface  of  the  Prairie  du  Chien  series. 


s  State  Geological  S 


GtOs.w*&'&L  SURVEY 
UBRaY 


STRUCTURE  2  3 

Stratigraphic  Relations 

The  St.  Peter  sandstone  is  unconformable  with  the  formations  above 
and  below  it  in  outcrops  throughout  the  State  except  in  Calhoun  County. 
The  unconformity  at  the  top  of  the  St.  Peter  is  in  general  undulating.  The 
maximum  local  relief  noted  was  about  50  feet.  The  unconformity  at  the 
base  of  the  sandstone  is  much  more  pronounced ;  it  has  a  local  relief  of  about 
350  feet  in  a  limited  area  at  joliet.  Elsewhere  similarly  abrupt  relief  of 
lesser  magnitude  is  suggested  by  well  records.  This  condition  is  thought, 
however,  to  be  largely  local,  and  the  exception  rather  than  the  rule. 

Structure 

The  map  (PI.  Ill)  showing  the  structure  of  the  top  of  the  St.  Peter  has 
been  made  from  well  records  and  outcrop  data.  The  character  of  the  data 
from  which  this  map  was  drawn  makes  generalization  a  necessity,  and  a  200- 
foot  contour  has  therefore  been  used.  Inasmuch  as  the  top  of  the  St.  Peter 
was  a  surface  of  erosion  before  its  deformation,  the  map  may  not  precisely 
indicate  the  actual  rock  structure.  Some  errors,  introduced  by  pronounced 
local  irregularities  in  the  top  of  the  sandstone,  may  be  large,  but  in  general 
the  map  is  thought  to  delineate  with  reasonable  accuracy  the  amount  and 
character  of  the  deformation  suffered  by  the  St.  Peter. 

The  principal  feature  shown  by  the  structure  map  is  the  La  Salle  anti- 
cline trending  northwest-southeast  through  Ottawa  and  La  Salle.  The 
Savanna-Sabula  anticline,  really  a  cross  fold  on  the  La  Salle  anticline,  is 
shown  extending  from  Savanna  in  Carroll  County  to  DeKalb  in  the  county 
of  the  same  name  and  causing  an  irregular,  hour-glass  shaped  dome  around 
Oregon  in  Ogle  County  where  the  two  anticlines  intersect.  A  slight  arch 
trending  northeast-southwest  is  also  shown  in  the  vicinity  of  Millington, 
Kendall  County.  This  is  partly  responsible  for  the  outcrops  of  the  St.  Peter 
sandstone  at  Millington  and  almost  continuously  along  Fox  River  from  its 
junction  with  the  Illinois  to  Sheridan.  There  is  also  a  suggestion  of  the 
Morris-Kankakee  anticline  extending  southeast  from  Morris,  Grundy  County. 
In  Calhoun  and  Jersey  counties  the  effects  of  the  Cap-au-Gres  fault  and  the 
attendant  folding  are  indicated.  In  the  vicinity  of  Waterloo  and  Thebes  the 
effects  of  the  uplift  of  the  Waterloo  and  Valmeyer  anticlines  at  the  former 
place  and  the  Thebes  anticline  at  the  latter  are  shown  by  the  comparatively 
shallow  depth  at  which  the  St.  Peter  is  encountered  here  as  compared  with 
the  region  adjoining. 

The  structure  map  (PI.  Ill)  not  only  is  of  scientific  interest  but  also  is 
of  value  in  the  determination  of  the  approximate  depth  to  the  sandstone  at 
any  given  place.  A  knowledge  of  this  depth  is  often  desirable  in  searching 
for  potable  water  supplies,  inasmuch  as  the  St.  Peter  is  a  very  important 
source  of  water  for  domestic  consumption.    Two  examples  will  serve  to  indi- 


26  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

cate  how  the  map  may  be  used  for  this  purpose.  (1)  A  given  town  has  an 
elevation  of  700  feet  above  sea  level.  On  the  structure  map  it  is  found  to  lie 
half  way  between  the  +200-  and  +  400-foot  contour  lines.  The  approximate 
elevation  of  St.  Peter  sandstone  beneath  this  town  is  therefore  about  300  feet 
above  sea  level.  The  depth  to  the  sandstone  at  the  town  is  the  difference 
between  the  elevations  of  the  surface  of  the  ground  and  of  the  top  of  the 
sandstone,  or  400  feet.  (2)  A  given  town  has  an  elevation  of  650  feet  above 
sea  level  and  on  the  structure  map  lies  one-fourth  of  the  distance  between 
the  — 400-  and  the  — 600- foot  contour  lines  from  the  400- foot  contour.  The 
elevation  of  the  top  of  the  St.  Peter  at  this  place  is  therefore  450  feet  below 
sea  level.  Since  the  town  is  above  sea  level  its  elevation  is  added  to  450  to 
give  the  depth  of  the  sandstone  or  1100  feet. 

Origin  of  the  St.  Peter  Sandstone 

The  origin  of  the  St.  Peter  sandstone  has  long  been  a  question  of  much 
interest  to  geologists.  Two  theories  have  been  advanced,  the  first  postulating 
the  St.  Peter  as  a  great  interior  desert  of  drifting  sand  before  burial  and  the 
second  considering  the  sandstone  as  a  sedimentary  deposit  essentially  marine 
in  origin.  The  most  recent  work  on  this  subject  is  that  of  Dake7  who  from 
a  comprehensive  study  of  the  St.  Peter  concludes  that  the  sandstone  is  princi- 
pally of  marine  origin  except  in  some  of  the  shore  phases,  that  the  source  of 
the  sand  was  the  pre-Cambrian  crystalline  rocks  and  the  Potsdam  sandstone 
exposed  in  the  -Canadian  shield  north  and  northwest  of  the  St.  Peter  basin, 
and  that  the  sand  was  transported  by  streams  from  its  source  area  to  the 
epicontinental  sea  in  which  it  was  deposited  and  distributed  principally  by 
waves  and  currents.  There  may  also  have  been  minor  distribution  of  beach 
sand  by  wind  into  dunes  and  related  deposits  which  later  were' buried  by  the 
advancing  sea.  The  evidence  on  which  his  conclusions  are  based,  and  a  state-, 
ment  of  them  in  summary  form  are  as  follows  :8  ";'^~ 

"1.  The  composition  and  texture  of  a  sandstone  may  furnish  criteria  regarding 
its  derivation  and  transportation,  but  not  regarding  its  method  of  deposition. 

2.  The  history  of  the  sand  grains  of  a  sandstone  is  usually  so  complex,  including 
transportation  successively  by  winds,  streams  and  waves,  that  textural  criteria  afford 
no  proof  whatever  of  the  nature  of  transportation  even  to  the  last  deposit  in  which  the 
sand  is  found.  The  complexity  of  this  history  may  be  still  further  increased,  if  the  sand 
passes  through  several  cycles,  from  solid  rock  through  sediment  to  solid  rock  again. 

3.  The  structural  and  stratigraphic  relationships  in  the  field,  including  such  fea- 
tures as  the  character  of  bedding,  cross-bedding,  unconformities,  lateral  gradation  and 
similar  associated  phenomena,  constitute  the  only  valid  criteria  for  determining  the 
conditions  under  which  a  deposit  was  last  laid  down,  and  these  may  sometimes  give  a 
clue  to  the  method  of  transportation  to  that  particular  resting  place. 

4.  The  purity  of  the  St.  Peter  sandstone,  while  very  remarkable,  as  compared  with 
that  of  average  sandstones,  is,  in  respect  to  content  of  clay,  iron,  mica,  heavy  minerals, 
and  carbonate,  not  sufficiently  different  from  that  of  associated  marine  sandstones  to 
demand   any  essentially  different  explanation  of  origin;  the  degree  of  difference   actually 

TDake,   C.  L.,  ThG  problem  of  the  St.   Peter  sandstone:     Univ.   of  Missouri   School   of 
Mines   rmd   Metallurgy  Bull.,   technical   series,  vol.    6,   No.   1,   p.    224,   August,   1921. 
BDake,    C.    T,..    op.    cit.,    t^T>.    221-224. 


us  State  Geological  S 


5    SXtf* 


«^ 


ORIGIN  27 

existing  being   satisfactorily    accounted   for   by   assuming  its   derivation   from   one   of   the 
older,   already  well-sorted  sandstones,  the  Potsdam. 

5.  Size  of  grain,  in  pure  quartz  sands,  in  general,  is  limited  by  the  size  of  quartz 
grains  in  average  igneous  rocks,  and  is  not  a  satisfactory  criterion  of  wind-blown  sands. 

6.  The  size  and  uniformity  of  grain  in  the  St.  Peter  is  so  near  that  of  the  Roubi- 
doux  marine  sand  that  no  discrimination  as  to  origin  can  be  made  on  such  a  basis. 

7.  The  degree  of  rounding  and  frosting  of  grains,  which  has  been  used  as  one  of 
the  chief  arguments  for  eolian  origin  of  the  St.  Peter,  may  often  be  masked  by  secondary 
quartz  enlargement,  but  making  due  allowance  for  such  modification,  the  St.  Peter  cannot 
be  distinguished  on  this  basis  from  the  marine  Roubidoux,  or  from  older  Cambrian 
sandstones,  so  that  it  is  quite  illogical  to  assume  a  different  explanation  for  one  than  for 
the  other. 

8.  The  St.  Peter  shows  bedding  better  developed  than  cross-bedding,  and  does  not 
show  typically  developed  dune-structure,  even  in  the  protected  basal  layers  In  the  valleys 
of  the  old  erosion  surface. 

9.  There  is  no  reason  why,  if  the  St.  Peter  is  a  dune  deposit,  an  encroaching  sea 
should  be  assumed  to  have  completely  worked  out  all  such,  structure,  and  yet  be  assumed 
to  have  allowed  it  to  be  preserved,  as  reported  in  the  Sylvania  sandstone. 

10.  The  St.  Peter  basal  conglomerate  of  chert  pebbles,  widely  developed  on  the 
pre-St.  Peter  erosion  surface,  shows  no  effect  of  wind-polishing  or  development  of 
facetted  pebbles  characteristic  of  work  done  by  drifting  sand.  Such  wind  modification 
would  surely  be  observable  if  the  St.  Peter  sand  was  drifted  extensively  across  the  area. 

11.  Limestone  layers  occur  at  many  horizons,  particularly  at  the  south,  but  are 
known  as  far  north  as  north  central  Iowa  and  northern  Illinois,  and  indicate  marine 
deposition. 

12.  Oscillation  ripple-marks  in  sand  layers,  marine  fossils  in  limestone  beds,  and 
extensive  limestone  deposits  in  general,  occur  in  Arkansas  and  Missouri,  next  above  the 
unconformity,  showing  submergence  before  the  advance  of  the  sand  into  the  region. 

13.  Marine  fossils  are  found  in  the  St.  Peter  as  far  north  as  Minneapolis,  not  only 
in  the  uppermost  transition  layers,  but  also  at  three  horizons,  more  than  60  feet  below 
the  top.     These  would  not  appear  to  have  resulted  from  working  over  of  dune  deposits. 

14.  The  St.  Peter  and  Roubidoux  appear  to  have  been  derived  from  a  common  land 
mass,  which  was  almost  certainly  located  to  the  northward,  on  the  present  site  of  the 
pre-Cambrian  shield. 

15.  This  land  mass  was  not  very  high,  sloped  toward  the  sea  at  the  south  in  which 
direction  its  rivers  flowed,  was  probably  moderately  humid,  but  without  vegetation 
because  land  plants  had  not  yet  developed,  and  lay  in  the  belt  of  prevailing  westerly 
winds. 

16.  Throughout  early  Paleozoic  times,  these  conditions  were  particularly  favorable 
for  wind  action,  the  westerly  winds  tending  to  float  the  finer  dust  and  clay  eastward 
across  a  continuous  land  mass  until  it  was  lost  in  the  Atlantic,  whereas  the  sand  was 
drifted  into  the  rivers  and  carried  south  to  the  sea,  thus  accounting  for  the  lack  of  the 
theoretically  proportionate  amount  of  clay  in  the  early  Paleozoic  sandstones. 

17.  The  wind  drifting  undoubtedly  was  also  an  important  factor  in  the  rounding 
and  frosting  of  sand  grains  in  all  the  early  Paleozoic  sandstones  from  Potsdam  to  St. 
Peter. 

18.  Since  these  winds  were  presumably  from  west  to  east  then  as  now,  being  con- 
trolled by  the  rotation  of  the  earth,  they  would  not  seem  competent  to  drift  the  St.  Peter 
sand  southward  from  its  place  of  origin  to  its  present  distribution. 

19.  The  land  mass  included  not  only  the  pre-Cambrian  mixed  crystallines,  but  also 
a  broad  fringe  of  Potsdam  sandstone,  which  was  exposed,  possibly  about  the  close  of 
Everton  time,  by  the  erosion  of  the  overlying  Beekmantown  limestones. 

20.  The  derivation  of  the  St.  Peter  largely  from  this  Potsdam  belt,  in  which  the 
sands  were  already  well  assorted  and  rounded,  together  with  the  added  sorting  and 
rounding  by  wind  work  in  the  supply  area,  and  by  waves  in  the  sea,  explains  in  a  wholly 
satisfactory  manner  the  high  degree  of  purity  and  rounding  of  its  grains. 

21.  These  sands  were  delivered  to  the  sea  both  by  rivers  and  to  a  minor  degree 
directly  by  winds,   and  were  distributed   chiefly  by  waves   and   currents. 


28  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

22.  The  shores  of  this  sea  were  fluctuating,  but  during  middle  and  late  St.  Peter 
time,  were  for  the  most  part  north  of  the  Iowa-Minnesota  line. 

23.  North  of  that  line  there  is  quite  probably  a  small  amount  of  St.  Peter  that  is 
truly  unmodified  terrestrial  deposit,  for  occasional  slight  local  emergences  not  improbably 
allowed  of  wind-drifting  and  rounding,  accounting  for  local  areas  of  exceptionally 
rounded  grains ;   but   even   here  marine    agencies   were   probably  dominant  in  deposition. 

24.  South  of  the  Iowa-Minnesota  line,  conditions  of  both  transportation  and  deposi- 
tion were  almost  wholly  marine,  and  in  this  area  there  did  not  exist  during  any  part  of 
St.  Peter  time,  a  great  interior  desert  of  drifting  sand.' 

The  data  secured  during  the  present  investigation  tend  to  corroborate 
Dake's  conclusions.  Additional  corroborative  evidence  of  marine  origin  is 
presented  along  live  different  lines. 

(1)  Worm  borings.  In  Chapter  III  worm  borings  are  described  from 
the  middle  St.  Peter  of  the  Ottawa  district.  Similar  borings  were  also  re- 
ported by  Freeman.9  The  borings  are  preserved  in  sandstone  doubtless  de- 
posited by  water  and  are  probably  the  borings  of  marine  worms,  suggesting 
marine  conditions  during  at  least  part  of  middle  St.  Peter  time. 

(2)  Ripple  marks.  The  upper  and  lower  St.  Peter  in  northern  Illinois 
and  the  middle  of  the  formation  in  Calhoun  County  contain  ripple  marks 
which  are  described  in  Chapter  III.  These  are  of  the  oscillation  type  com- 
monly developed  in  shallow  water. 

(3)  Dessication  or  sun  cracks.  In  Chapter  III  dessication  cracks  are 
described  from  the  middle  St.  Peter  in  sandstone  with  a  high  clay  and  prob- 
ably a  high  colloidal  silica  content.  The  presence  of  these  cracks  in  well- 
stratified  sandstone  in  horizontal  and  parallel  beds  suggests  temporary  emer- 
gence and  subsequent  submergence  of  water-laid  sediments. 

(4)  Uniform  character  of  clay.  As  suggested  in  Chapter  III  the  uni- 
form character  of  the  clay  of  the  St.  Peter  is  best  explained  by  postulating  a 
principally  marine  origin  for  this  material. 

(5)  Relation  of  bedding  and  cross-bedding.  Dake's  contention  that 
bedding  in  the  St.  Peter  is  far  more  important  than  cross-bedding  is  thor- 
oughly confirmed  from  the  detailed  study  of  the  St.  Peter  of  Illinois.  This 
is  thought  to  favor  marine  origin  for  the  bedded  sandstone.  Furthermore, 
such  cross-bedding  as  is  present  in  the  Illinois  St.  Peter  is  generally  of  the 
aqueous  rather  than  the  eolian  type. 

(6)  Similarity  between  the  St.  Peter  sand  and  the  Nezv  Richmond  sand. 
A  comparison  of  the  shape,  size,  degree  of  rounding,  frosting,  and  texture  of 
samples  of  St.  Peter  sand  and  the  New  Richmond  sand  from  outcrops  in 
Illinois  fails  to  reveal  any  significant  difference  between  the  two.  Two  un- 
labeled samples  of  these  sands  would  be  indistinguishable.  The  sieve  anaylsis 
of  a  sample  of  New  Richmond  is  given  in  the  table  of  fineness  tests  (Table 
10,  No.  59).  The  presence  of  the  New  Richmond  formation  of  interbedded 
limestone  of  marine  origin  suggests  that  the  sandstone  may  also  be  marine, 


oFreeman,   S.   II.,  Geology  of  Illinois,  "La  Salle  County,  vol.   3,  p.   280,   1882. 


GEOLOGIC    HISTORY  29 

and  that  sand  of  the  physical  character  of  the  St.  Peter  may  accumulate  as  a 
marine  deposit. 

(7)  Limestone  and  dolomite.  The  presence  of  limestone  or  dolomite 
beds  in  the  St.  Peter  of  Lake,  Cook  and  Adams  counties  (see  p.  50)  indi- 
cates that  in  parts  of  Illinois  at  least  some  of  the  formation  is  marine  in  origin 
and  suggests  that  parts  of  the  sandstone  elsewhere  in  the  State  may  have  had 
a  similar  origin. 

Geologic  History 

After  the  deposition  of  the  Shakopee  formation  in  Illinois,  a  period  of 
uplift,  accompanied  by  slight  deformation,  occurred  and  a  long  period  of 
erosion  ensued.  It  is  doubtful  if  erosion  was  very  rapid  despite  the  fact  that 
streams  cut  deep  valleys  in  the  Shakopee,  for  in  places  there  accumulated  on 
comparatively  narrow  divides  considerable  thicknesses  of  residual  clay.  It 
seems  likely  therefore  that  solution  played  a  very  important  part  in  shaping 
the  pre-St.  Peter  land  mass.  In  many  places  the  residuum  from  the  limestone 
seems  to  have  been  cleaned  largely  of  clay  and  to  have  consisted  principally 
of  residual  chert  fragments. 

The  St.  Peter  sea  advanced  on  a  land  mass  of  considerable  dissection. 
The  result  was  many  drowned  valleys  and  irregular  submerged  areas.  Some 
of  these  areas  were  out  of  direct  communication  with  the  streams  bringing 
the  sand  into  the  sea  and  in  them  the  sediments  of  early  St.  Peter  time  were 
largely  residual  material  from  the  Shakopee  carried  down  by  the  surface  run- 
off, and  a  little  sand.  The  sandy  shales  in  the  base  of  the  St.  Peter  are 
doubtless  of  this  origin.  In  places  the  waves  and  currents  working  on  the 
Shakopee  land  mass  cleaned  away  the  clay  and  carried  it  to  deeper  and  quieter 
water  where  it  was  deposited  interstratifled  with  sand.  During  the  trans- 
gression of  the  land  by  the  sea.  residual  cherts  from  the  limestone  became 
available  to  the  waves  and  currents  and  were  mixed  with  the  sand  thus  yield- 
ing the  sandstone  and  chert  so  commonly  reported  in  the  lower  St.  Peter. 
In  other  places  it  appears  that  the  waves  and  currents  were  principally  de- 
positing their  loads  and  that  temporary  beaches,  bars  and  sand}-  flats  were 
formed.  The  sand,  in  such  places  where  the  winds  carried  it  landward, 
buried  the  deposits  on  the  old  Shakopee  land  mass  and,  as  submergence 
ensued,  the  waves  and  currents  reworked,  at  least  partially,  the  wind-blown 
sand  but  apparently  did  not  work  deeply  enough  to  disturb  the  underlying 
materials  to  any  great  extent,  probably  because  the  St.  Peter  sea  was  essen- 
tially a  depositing  rather  than  an  eroding  sea.  Thus  it  seems  that  some  of 
the  red  clay  found  on  what  appear  to  be  Shakopee  divides,  may  have  been 
preserved  through  the  transgressional  period  of  the  early  St.  Peter  sea.  In 
local,  quiet  areas  intimately  mixed  sand  and  clay  were  deposited,  together 
with  some  calcareous  material.  The  clay  and  calcareous  material  served  to 
bond  the  sand  and  to  preserve  the  ripple  marks  of  that  early  sea. 


30  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

The  source  of  the  St.  Peter  sand  was  probably  the  pre-Cambrian  crys- 
tallines of  the  Canadian  shield  and  the  Cambrian  and  early  Ordovician  sand- 
stones lying  north  of  the  area  of  St.  Peter  deposition.10  The  fact  that  the 
crystallines  were  probably  well  weathered  and  the  Cambrian  sandstones  not 
very  firmly  cemented  doubtless  resulted  in  an  abundant  and  readily  available 
supply  of  sand  to  the  agencies  transporting  it  to  the  area  of  St.  Peter  depo- 
sition. Gradual  and  continued  depression  of  the  St.  Peter  basin  resulted  in 
practically  continuous  deposition  of  sand  in  Illinois  during  the  greater  part  of 
middle  and  late  St.  Peter  time  though  in  places,  especially  during  late  .St. 
Peter  time,  areas  existed  where  conditions  were  favorable  for  the  accumula- 
tion of  calcarerous  and  dolomitic  muds,  as  evinced  by  the  presence  of  lime- 
stone and  dolomite  in  the  middle  St.  Peter. 

In  the  Calhoun  County  area  deposition  was  apparently  continuous  from 
St.  Peter  to  Joachim  time,  with  a  gradual  change  in  the  character  of  the  sea 
from  one  depositing  sand  to  one  depositing  calcarerous  material.  In  northern 
Illinois,  however,  the  upper  St.  Peter  sediments  have  been  removed  by 
erosion,  and  consequently  the  events  of  late  St.  Peter  time  are  not  decipher- 
able. It  cannot  be  definitely  stated  whether  or  not  the  Joachim  dolomite 
existed  in  northern  Illinois,  but  if  it  did  exist  it  was  eroded  before  the  depo- 
sition of  the  Platteville  sediments. 

The  erosion  occurring  in  northern  Illinois  after  the  close  of  St.  Peter 
deposition  and  before  the  deposition  of  the  next  overlying  formation  was 
apparently  not  severe.  Probably  the  land  was  not  high  above  the  sea.  The 
result  was  the  development  of  a  subeven  surface  which  is  now  the  contact 
between  the  St.  Peter  and  the  overlying  beds. 

Following  this  period  of  erosion  the  land  was  again  submerged  and  in  a 
part  of  northern  Illinois  clay  mixed  with  St.  Peter  sand  was  deposited  mak- 
ing the  Glenwood  formation.  Elsewhere  in  Illinois,  the  sea  seems  to  have 
been  free  from  muds  and  the  sand  of  the  St.  Peter  was  overlaid  by  deposits 
of  lime  muds  and  fossil  debris  which  later  became  the  Platteville-Galena 
limestone  and  dolomite. 

Folding  of  the  La  Salle  anticline  took  place  principally  some  time  after 
Galena  time  and  before  Pennsylvanian  times11  and  subsequent  to  this  folding 
erosion  removed  the  beds  overlying  the  St.  Peter  in  the  La  Salle  area.  With 
the  submergence  during  the  Pennsylvanian  period  a  clay  mixed  with  sand 
derived  from  the  St.  Peter  was  deposited  by  the  Pennsylvanian  sea. 

With  the  close  of  Pennsylvanian  time  the  land  again  appears  to  have 
been  uplifted  and  the  erosion  which  is  partly  responsible  for  the  present 
ron figuration  of  the  bed  rocks  of  the  State  began.  Later,  during  the  Pleis- 
tocene or  glacial  period,  at  least  two  continental  ice-sheets  overspread  the 


lODake,   C.  L.,   op.   qit.,   p.   207. 

iiC;i.riy,    (!.    ||.,    The   structure   of   the   L,a   Salle   anticline:      Illinois    State   Geol.    Survey 
Bull.    36,    p.    174,    1*)20. 


GEOLOGIC    HISTORY  31 

then  existing  outcrops  of  St.  Peter  and  in  places  buried  them  with  a  deposit 
of  glacial  clay  and  gravel.  The  swollen  streams  associated  with  the  melting 
of  these  glaciers  were  further  effective  in  eroding  the  St.  Peter  in  northern 
Illinois  and  it  is  probable  that  these  glacial  waters  of  Illinois  and  Fox  rivers 
were  in  a  large  measure  responsible  for  the  development  of  the  rock  terraces 
in  the  valleys  of  these  streams.  Subsequent  and  recent  erosion  has  removed 
some  of  the  glacial  drift  from  the  outcrops  of  St.  Peter  and  is  to  a  large 
extent  responsible  for  the  present  minor  details  of  topography. 


CHAPTER  III— SPECIAL  LITHOLOG1C,  STRUCTURAL,  AND, 

COMPOSITIONAL  FEATURES  OF  THE  ST.  PETER 

SANDSTONE 

Introduction 

In  Chapter  II  the  general  areal  geology  and  lithologic  character  of  the 
St.  Peter  sandstone  are  described  and  some  of  the  special  features  of  a  litho- 
logic, structural,  and  compositional  nature  are  alluded  to.  In  this  chapter 
these  special  features  are  discussed  in  detail. 

Structural  Features 

bedding 

In  general  the  St.  Peter  may  be  said  to  be  a  bedded  sandstone,  though 
the  bedding  is  thicker  and  less  apparent  than  that  common  to  sandstones. 
The  thickness  of  the  St.  Peter  beds  varies  from  3  to  10  or  12  feet,  though 
locally  much  thinner  beds  are  present.  In  the  molding  sand  quarries  in  the 
Illinois  River  bluff  west  of  the  center  of  sec.  13,  T.  33  N.,  R.  2  E..  the  upper 
beds  exposed  are  thin,  varying  from  1  to  5  inches  in  thickness  and  averaging 
about  3  inches.  In  the  glass  sand  quarries  occur  locally  layers  of  thin-bedded 
sandstone  with  a  highly  siliceous  cement.  In  some  places  the  bedding  planes 
are  clearly  brought  out  by  a  deposit  of  iron  hydroxide  along  them,  but 
commonly  the  general  absence  of  considerable  amounts  of  clay  or  other  im- 
purities causes  the  sandstone  to  appear  non-bedded  on  casual  examination. 
Bedding  planes  are  in  general  not  marked  and  the  most  reliable  method  of 
determining  bedding  is  observation  of  the  sandstone  from  a  distance  or  close 
examination  of  the  variations  in  the  size  of  the  dominant  grain  of  a  vertical 
section. 

CROSS-BEDDING 

Cross-bedding  is  not  common  in  the  St.  Peter  but  is  well  developed  in 
some  places,  particularly  in  the  quarries  of  the  Wedron  and  United  States 
Silica  Companies  (figs.  5  and  9).  In  general  the  cross-bedded  zones  are  not 
more  than  3  feet  thick.  In  the  quarry  of  the  United  States  Silica  Company 
(fig.  9),  the  exposure  consists  of  a  single  cross-bedded  stratum  about  3  feet 
thick  and  also  of  cross-bedded  strata  inclined  in  a  number  of  directions  with 
the  different  sets  of  beds  truncating  or  truncated  by  others.  Most  of  the  cross- 
bedding  noted  in  the  St.  Peter  generally  was  in  the  middle  portion  of  the 
formation  though  it  also  occurs  elsewhere  in  the  formation.    Both  fluvial  and 

32 


STRUCTURAL    FEATURES 


33 


probably  eolian  cross-bedding  is  present  in  the  St.  Peter  though  the  former 
is  far  more  common. 

Another  feature  of  the  St.  Peter  is  the  "sheety"  structure  which  is  com- 
monly developed  in  weathered  and  some  fresh  exposures  (figs.  6  and  21). 
Almost  all  of  the  sheety  planes  are  inclined  at  a  steep  angle  to  the  face  of  the 
exposure  and  their  strike  is  generally  roughly  parallel  to  it.  The  origin  of  the 
structure  is  not  known,  but  it  is  thought  that  it  may  be  a  phenomenon  of  bed- 
ding, or  of  the  weathering  of  a  rather  homogeneous  sand,  or  of  fracturing. 


Fig.  5.  Cross-bedding-  in  the  St.  Peter  sandstone  in  the  quarry  of  the 
Wedron  Silica  Company.  The  knife  indicates  the  comparative  size  of 
the  cross-bedded  layers.  The  black  specks  along  some  of  the  bedding 
planes  at  the  right  of  the  picture  are  small  masses  of  interstitial 
marcasite. 


RIPPLE  MARKS 

In  general  ripple  marks  are  rare  in  the  St.  Peter  sandstone.  Their 
absence  is  not  thought  to  indicate  that  they  did  not  exist  in  the  St.  Peter  sea, 
but  rather  that  conditions  were  not  favorable  for  their  preservation.  The 
most  extensively  ripple-marked  sandstone  noted  was  that  exposed  in  Calhoun 
County  between  Dogtown  Landing  in  the  SW.  corner  sec.  29,  T.  12  S.,  R.  2 
W.,  and  West  Point  Landing  about  a  mile  north.  The  ripple  marks  are  of 
the  oscillation  type,  and  vary  from  1  to  \y2  inches  from  crest  to  crest  and 
average  about  y^  inch  in  depth.     They  commonly  anastomose. 


54 


THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


In  northern  Illinois  ripple  marks  were  observed  principally  in  the  lower 
part  of  the  St.  Peter.  The  ripple-marked  slab  shown  in  figure  7  was  found 
in  an  outcrop  of  lower  St.  Peter  in  the  north  bank  of  Franklin  Creek  in  the 
NW.  yA  NE.  Yx  sec.  33,  T.  22  N.,  R.  10  E.  The  ripple  marks  in  this  ex- 
posure as  a  whole  are  of  two  kinds :  those  which  are  straight  and  roughly 
parallel,   measuring  about  one  inch   from   crest  to   crest,   and  those  which 


Fig.  6.  Exposure  of  St.  Peter  sandstone  in  the  quarry  of 
the  Wedron  Silica  Company  showing  in  the  left  hand 
portion  the  "sheety"  structure  of  the  sandstone  and  on 
the  right  the  face  of  one  side  of  a  joint.  The  black 
streakings  on  this  face  are  thin  sheets  of  marcasite. 


anastomose,  averaging  about  2>y2  inches  from  crest  to  crest  and  about  y2  inch 
in  depth.    Both  are  of  the  oscillation  type. 

Other  exposures  of  ripple-marked  sandstone  were  found  in  the  small 
gullies  in  the  northeast  bank  of  Franklin  Creek  in  the  NE.  corner  sec.  3,  T. 
21  N.,  R.  10  E.,  and  vicinity.  The  ripple  marks  are  of  the  oscillation  type 
and  vary  from  \y>  to  3  inches  from  crest  to  crest  and  average  y2  inch  in 
depth.     The  trend  of  the  troughs  of  these  ripple  marks  is  roughly  N.  30°  W. 


STRUCTURAL    FEATURES 


3  5 


The  only  ripple  marks  noted  in  the  upper  St.  Peter  were  found  north- 
west of  Shirland  in  Winnebago  County  near  the  center  of  sec.  32,  T.  29  N., 
R.  11  E.,  in  the  south  bank  of  Sugar  River.     They  are  of  the  oscillation  type. 

An  attempt  was  made  to  locate  the  eolian  ripple  marks  in  Ogle  County 
mentioned  by  Worthen.1  However,  it  was  impossible  to  find  the  locality 
from  the  data  given. 


Fig.  7.  Slab  of  ripple-marked  St.  Peter  sandstone 
from  outcrop  in  NW.  ^  NE.  ^  sec.  33,  T.  22  N., 
R.   10  E.      (One-sixth  natural  size.) 


HONEYCOMB    WEATHERING 

In  places  weathered  faces  of  St.  Peter  are  covered  with  a  large  number 
of  pits  so  arranged  that  they  give  the  appearance  of  a  honeycomb  to  the  sur- 
face of  the  rock.  This  phenomenon  is  known  as  honeycomb  weathering  and 
is  commonly  ascribed  to  the  process  of  differential  weathering  of  sandstone 
with  an  unequally  distributed  cement.  It  is  very  well  shown  in  Council  Cave 
in  the  NW.  yA  sec.  25,  T.  33  N.,  F.  2  E. 

i  Worthen.    A.   H.,    Geology   of  Illinois.      Ogle   County,    vol.    3.    p.    18.    18S2. 


36 


THE    ST.    PETER    SANDSTONE   OF    ILLINOIS 


WORM   BORINGS 

In  some  of  the  quarries  in  the  St.  Peter  sandstone,  especially  those  of 
the  United  States  and  Commonwealth  Silica  Companies,  there  are  beds  of 
sandstone  of  finer  grain  and  more  firmly  cemented  than  the  rest  of  the  deposit 
which  contain  roughly  vertical  tubes  from  ^  to  ^  inch  in  diameter  filled 
with  sand  which  is  coarser  than  the  matrix.  The  original  tubular  openings 
are  thought  to  have  been  made  by  worms  and  subsequently  filled  by  coarser 
sand  washed  into  the  borings  (fig.  8).  These  borings  are  probably  similar  to 
those  noted  in  the  St.  Peter  of  the  same  region  by  Freeman.2 


Fig.  8.     Worm  borings  in  the  St.  Peter  sandstone. 

Worm  borings  have  also  been  described3  from  the  exposures  at  the  south 
end  of  the  Rock  River  bridge  at  Grand  Detour  65  feet  below  the  top  of  the 
formation,  and  in  the  NE.  y^  sec.  23  N.,  R.  10  E.,  10  feet  from  the  top 
of  the  sandstone.  The  borings  were  identified  as  Scolithus  minnesotensis 
Hall. 

DESSICATTON  OR  SUN   CRACKS 

In  the  glass-sand  quarry  of  the  Higby-Reynolds  Silica  Corupany  (Rey- 
nolds cast   quarry)    some  of  the  thinner  and  more  firmly  cemented  upper 


:'lw<cm;m.    S.    II.,   (Jeology   of    Illinois,    vol.    3,   p.    280,    1882. 

K'n;i|»|H  ii,     \i.    S.,    The    geology    and    mineral    resources    of    the    Dixon    quadrangle: 
Illinois  Stale  (',,;,].   Survey  Bull.   49,  p.   51,    1926. 


COMPOSITIONAL    FEATURES  37 

beds  containing  a  high  content  of  fine  silica,  possibly  of  colloidal  origin,  show 
dessication  cracks  filled  with  sand.  This  phenomenon  was  also  noted  locally 
in  thin-bedded  strata  in  other  quarries  but  was  best  and  most  commonly 
exposed  in  the  Reynolds  quarry. 

Compositional  Features 
carbonaceous  bands 

Locally  thin  horizontal  or  approximately  vertical  bands  of  carbonaceous 
or  fibrous  organic  materials,  rarely  over  y2  inch  thick,  were  noted  in  the 
upper  few  feet  of  the  St.  Peter.  The  best  exposures  were  seen  in  the  west 
face  of  the  quarry  of  the  National  Silica  Company  at  Oregon.  They  have 
been  formed  from  rootlets  which  penetrated  into  the  sandstone  through 
cracks  and  spread  out  laterally  in  porous  or  soft  portions  of  the  sandstone. 

CLAY  POCKETS 

In  the  molding  sand  quarries  in  the  Illinois  River  bluff  between  Ottawa 
and  Utica  deposits  of  clay  are  found  locally  in  depressions  in  the  surface  of 
the  St.  Peter  sandstone.  The  depressions  are  commonly  roughly  conical  and 
approximately  round.  The  largest  of  the  clay  pockets  observed  was  about 
12  feet  in  diameter  and  had  been  excavated  to  a  depth  of  about  8  feet  without 
reaching  bottom  and  probably  extended  at  least  8  feet  deeper.  At  the  quarry 
of  the  Illinois  Valley  Silica  Company  it  is  reported  that  three  clay  pockets 
were  encountered,  a  large  central  pit  with  a  smaller  pit  on  either  side  of  it. 
The  small  pits  were  connected  with  the  large  pit.  The  small  pits  were  about 
10  feet  deep;  the  large  one  was  65  feet  deep,  15  feet  in  diameter  at  the  top 
and  8  feet  at  the  bottom.  The  clay  filling  these  depressions  is  similar  to  that 
which  overlies  the  sandstone  in  the  region  where  the  depression  occurs.  So 
far  as  could  be  ascertained  these  pockets  are  entirely  filled  with  clay  and 
contain  no  boulders  or  extraneous  material  in  their  lower  portions.  Their 
origin  is  not  known,  but  it  may  be  suggested  that  they  are  the  result  of 
differential  erosion  by  water  or  wind  of  a  portion  of  the  sandstone  less  firmly 
cemented  than  the  rest,  and  that  this  erosion,  if  by  wind,  took  place  immedi- 
ately before  the  submergence  which  permitted  the  deposition  of  the  overlving 
clay ;    otherwise  the  depressions  would  probably  have  been  obliterated. 

INTERSTITIAL   ORGANIC    MATERIAL 

In  the  quarries  of  the  Standard  Silica  Company  (Plant  No.  1)  and  of 
the  National  Plate  Glass  Company  there  are  present  locally,  in  the  upper 
portions  of  the  exposures,  bands  of  sand  of  a  much  darker  color  than  that 
due  to  the  presence  of  iron.  At  the  Standard  quarry  the  exposure  of  these 
brown  bands  was  as  follows : 


38  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

6.  Soil,  black  Feet 

5.  Sandstone,  brown    1 

4.  Sandstone,  gray   white   - 3 

3 .  S andstone,  brown    3 

2.  Sandstone,  gray   white   4 

1.  Sandstone,  brown     1 

A  test  made  on  a  sample  of  sand  from  bed  No.  3  showed  that  the  color 
was  not  due  to  iron  but  to  the  presence  of  between  0.1  and  0.2  per  cent  of 
organic  material  which  occurs  as  a  coating  on  the  sand  grains  and  mixed 
with  the  interstitial  clay.  It  is  probable  that  descending  water  carried  this 
organic  material  down  into  the  sandstone  and  that  different  positions  of  the 
ground-water  table  governed  its  deposition. 


Fig.    9.      ''Magnesia"    bed     (indicated    by    arrow)     and    cross-bedded    sandstone    in    the 
quarry  of  the  United  States  Silica  Company. 

''magnesia"  BEDS 


In  certain  of  the  St.  Peter  quarries  there  are  present,  usually  in  the 
middle  portion  of  the  formation,  beds  of  thin-bedded,  fine-grained  sandstone 
relatively  high  in  clay  and  relatively  firmly  cemented,  known  as  "magnesia" 
beds  in  the  parlance  of  the  quarrymen  (fig.  9).  They  are  the  most  persistent 
stratigraphic  and  lithologic  unit  found  in  the  St.  Peter  of  Illinois.  They  vary 
from  a  few  inches  to  3  or  4  feet  in  thickness  and  contain  most  of  the  recog- 
nizable worm  borings  and  sun  cracks  found  in  the  exposures  of  the  St.  Peter 
in  Illinois.    They  are  equally  stained  or  mottled  pink  or  yellow  by  iron  oxides. 


COMPOSITIONAL    FEATURES 


The  analysis  of  sample  13a  taken  from  the  bed  shown  in  figure  9  is  repre- 
sented graphically  in  figure  10.  It  bears  out  the  statement  regarding  the 
fineness  and  clay  content  of  this  type  of  material  and  shows  that  48  per  cent 
of  the  sample  is  finer  than  65  mesh,  12.3  per  cent  finer  than  200  mesh,  and 
5.8  per  cent  clay.  Another  sample,  No.  31,  from  a  somewhat  thicker  bed  of 
the  same  sort,  contained  22.5  per  cent  finer  than  65  mesh,  but  only  2.2  per 
cent  finer  than  200  mesh. 

It  is  doubtless  these  beds  to  which  Littlefield  refers4  when  he  speaks  of 
the  presence  of  magnesium  in  the  middle  portion  of  the  St.  Peter.  None  of 
the  samples  tested  during  the  present  investigation  contained  an  appreciable 
amount  of  magnesium,  and  the  term  ''magnesia"  for  these  beds  seems  there- 
fore somewhat  of  a  misnomer.  It  may  be,  however,  that  they  represent  a 
leached  phase  of  the  sandy  limestones  or  dolomites  reported  elsewhere  in  the 
State,  and  so  may  in  places  contain  small  amounts  of  magnesium  carbonate 
or  oxide. 


Clay 
1.3  percent 


Magnesia 
sand 


Clay 
5.8  percent 


PERCENT 


Fig.  10.     Graphs  showing  texture  of  typical   St.  Peter  sand  and  of 
"magnesia"  sand   (sample  13a). 


SILICEOUS   JOINT  FILLINGS 

In  many  places  joints  in  the  St.  Peter  sandstone  have  been  partly  or 
wholly  filled  by  secondary  deposits  of  silica  in  which  are  usually  included  a 
number  of  medium  or  coarse,  rounded  sand  grains.  The  secondary  silica  is 
commonly  opaque  and  white  and  has  a  dull  luster.  It  is  thought  that  these 
joint  fillings  have  been  formed  by  precipitation  of  silica  from  ground  water 
and  that  the  sand  grains  were  mechanically  enmeshed  in  the  deposit. 

The  siliceous  deposit  commonly  scales  off  parallel  to  the  faces  of  the 
joint  which  it  fills.  In  some  places  where  most  of  the  deposit  has  scaled  off 
the  partly  impregnated  joint  face  which  has  been  left  bare  appears  to  have  a 
poorly  slickensided  surface  (fig.  11).  When  outcrops  containing  these 
siliceous  veins  weather,  the  friable  sandstone  adjoining  the  vein  is  removed 
and  the  veins  are  left  as  dike-like  ridges. 


•JLittlefield,   M.    S.,   Natural-bonded    molding 
Geol.   Survey  Bull.   50,   p.   124,    1925. 


sand   resources   of   Illinois  ::  Illinois   State 


40 


THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


Features  of  the  Sand  Grains 


size 


As  shown  by  the  table  of  sieve  analyses   (p.  148)  the  maximum  quan- 
tity of  sand  retained  on  the  20-mesh  sieve  was  0.7  per  cent,  and  in  general 


Fi#.  11.  Eroded  siliceous  veins  in  the  unworked  portion 
of  the  quarry  of  the  Ottawa  Silica  Company.  Note  the 
pseudo-slickensided  surface  of  the  rock  in  the  upper 
left   hand    portion  of  the  picture. 

almost  all  of  (he  sand  retained  on  (his  sieve  will  pass  16  mesh.     It  may  be 
safely  said,  there! ore,  that   for  all  practical  purposes  the  maximum  size  of  the 


SIZE    OF   SAND    GRAINS 


41 


grains  of  the  St.  Peter  sand  is  through  a  16  mesh  and  on  a  20  mesh  (0.711 
to  1.000  mm.).  The  smallest  sieve  size  determined  was  through  270  mesh 
(about  0.056  mm.).     A  maximum  of  4.0  per  cent  of  material  of  this  size  is 


Ottawa  Silica  Co.    6foot  bed 

Samples  400  feet  apart 

= ' !  • . ; ;  • '. 

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Benson  -  Richards  Sand  Co.     5  foot  bed 


Samples  300  feet  apart 


Wedron  Silica  Co.  8foot  bed 


Samples  450  feet  apart 


TTTTTTTTTj] 


tWIH  II    I 

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19 


20 


100 


,150 


illliliililiilii! 


!lli!i!i!iil!!ili!i!iiliiiiiiliiHi 


Ballou  White  Sand  Co.  11  foot  bed 


Samples  300  feet  apart 


II 
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ipo 


Fig.    12.     Sieve    analyses    of    sand    from    given    beds    in    four    different    quarries. 
Sample  numbers  are  indicated  at  right  of  diagram. 


shown  by  the  analyses.  The  sample  containing  this  maximum  amount  was 
taken  from  a  weathered  outcrop  and  may  possibly  have  been  somewhat  influ- 
enced by  mechanical  weathering.    The  maximum  quantity  of  material  from 


42  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

an  unweathered  sandstone  passing  the  270-mesh  sieve  was  1.5  per  cent.  The 
analyses  show  that  in  general  the  bulk  of  the  sand  grains  will  pass  a  28-mesh 
sieve  and  be  retained  on  100  mesh. 

In  order  to  determine  the  persistence  of  the  physical  composition  of 
given  beds  of  the  St.  Peter,  eight  samples,  two  from  each  of  four  different 
exposures,  were  taken  which  were  designated  "bed"  samples.  They  were  not 
taken  from  the  same  bed  in  the  four  outcrops,  but  both  samples  from  a  given 
quarry  came  from  one  bed.  The  sieve  analyses  of  these  bed  samples  are 
given  in  the  table  of  fineness  tests  (Table  10,  p.  148)  and  are  also  indicated 
graphically  in  figure  12.  The  outstanding  features  shown  are  as  follows: 
Samples  4  and  5  show  rather  striking  similarity  indicating  a  bed  of  uniform 
texture  and  relative  coarseness.  Samples  15  and  16  show  a  marked  variation 
in  the  amount  of  35-mesh  sand  present  and  minor  variations  in  the  rest  of 
the  sizes.  The  sand  is  in  general  of  a  medium  size.  Samples  19  and  20  are 
both  fine;  the  bulk  of  the  sand  passes  the  35-mesh  sieve.  The  principal 
variations  in  the  graphs  of  these  two  sands  occur  in  the  amounts  of  sand 
retained  on  the  48-mesh  sieve  and  on  the  100-mesh  sieve.  The  sand  of  sam- 
ples 48  and  49  is  also  fine.  The  chief  variations  in  these  samples  are  also  in 
the  amounts  of  sand  retained  on  the  48-  and  100-mesh  sieve.  From  these 
graphs  it  would  seem  that  in  general  there  is  considerable  variation  in  the 
texture  of  the  sand  in  the  beds  of  the  St.  Peter. 

In  order  to  determine  the  variation  in  the  texture  of  the  sandstone  in 
larger  units,  a  series  of  sieve  analyses  were  conducted  in  the  field  on  samples 
taken  from  three  different  faces  of  the  quarry  of  the  Ottawa  Silica  Company 
essentially  comprised  of  the  same  beds,  and  the  results  are  shown  graphically 
in  figure  13.  Of  note  in  these  graphs  is  the  variation  in  size  of  the  sands  of 
the  different  beds  sampled.  There  are  a  few  coincidences  in  the  analyses  of 
the  sands  in  beds  in  the  different  faces.  In  the  west  face  the  sand  from  8  to 
11  feet  above  the  floor  of  the  quarry  shows  a  close  similarity  to  the  sand 
from  7y2  to  \2y2  feet  in  the  south  face;  the  sands  from  15^  to  18^  feet 
in  the  west  face  and  from  21^2  to  25^4  in  the  south  face  show  equal  amounts 
of  30  and  40  mesh.  There  are  no  similarities  between  the  graphs  from  the 
south  and  east  faces.  The  east  and  west  faces,  however,  show  a  similar 
texture  in  the  beds  from  13  to  17  and  11  to  13  feet  respectively.  The  average 
analyses  indicate  the  average  for  the  entire  face.5  The  results  of  similar 
analyses  made  in  the  laboratory  on  samples  taken  in  the  same  quarry  at  about 
the  same  places  are  shown  in  figure  14.  Because  field  analyses  were  deter- 
mined by  volume,  and  laboratory  analyses  by  weight,  they  are  not  directly 
comparable. 

Figure  1  5  shows  graphically  sieve  analyses  of  the  samples  from  a  num- 
ber of  quarries  selected  so  as  to  represent  the  St.  Peter  geographically.     The 


uThis  average  is  weighted  so  that  it  takes  into  consideration  the  thickness  of  the  beds 
used  In  making  the  calculation. 


SIZE    OF   SAND    GRAINS 


43 


Face  No.l   West  end  quarry 


+30 


+  40 


+  60 


sa ■ 

Wm               lllll 

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28.5 
26.5 

21.5 
18.5 

15.5 

13 
11 


Face  No.2   South  face 


Face  No.3   East  face  quarry 


Fig.  13.  Sieve  analyses  made  in  the  field  of  samples  taken  bed  by  bed  from  the 
east,  west,  and  south  faces  of  the  quarry,  plant  A,  Ottawa  Silica  Company. 
The  figures  at  the  right  indicate  the  height  of  the  tops  of  the  beds  above  the 
quarry  floor.     The  percentages  are  by  volume. 


44 


THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 


first  three  samples,  Nos.  45,  43  and  7,  are  coarse  sands  as  shown  by  the 
graphs  and  by  the  table  of  fineness  tests  (Table  10).  They  come  from 
quarries  near  the  eastern  edge  of  the  St.  Peter  sandstone  outcrop,  and  are 
from  the  top  of  the  formation  as  it  is  found  now.  The  samples  in  order 
from  left  to  right  are  taken  farther  and  farther  west  in  the  outcrop  in  Illinois 
Valley,  and  include  progressively  lower  strata  of  the  St.  Peter.  Sample  36 
is  the  lowest  one  available  in  the  Ottawa-Utica  district  and  probably  comes 
from  the  middle  portion  of  the  St.  Peter.  From  the  graphs  it  appears  that 
the  upper  part  of  the  St.  Peter  in  the  Ottawa-Utica  district  is  in  general  the 
coarsest  part,  with  a  gradual  and  not  altogether  constant  decrease  in  the 
degree  of  coarseness  toward  the  middle  portion  of  the  formation. 

Samples  18,  47,  52  and  60/61  come  from  outlying  outcrops  of  the  St. 
Peter  and  are  included  to  show  the  comparative  size  of  the  sand  found  away 


l-West  end  of  quarry 


2-Center  of  south 
face  of  quarry 


3-Southeast  corner 
of  quarry 


Distance  from  1  to  2 —  500  feet 
Distance  from  1  to  3 — 1600  feet 
Distance  from  2  to  3—1200  feet 

Fig.  14.     Sieve  analyses  in  per  cent  by  weight  of  face  samples  from 
the  quarry  of  plant  A,  Ottawa  Silica  Company. 

from  the  Ottawa-Utica  district  It  will  be  noted  that  these  four  samples  are 
fine  sands.  With  the  exception  of  60/61  the  samples  have  been  taken  from 
the  upper  and  upper  middle  parts  of  the  St.  Peter.  The  Calhoun  County 
samples  come  principally  from  the  middle  portion  of  the  formation. 


SHAPE 

The  sand  of  the  St.  Peter  formation  is  widely  and  justly  known  as  a 
"rounded"  sand  but  the  use  of  the  adjective  has  often  inferred  that  the  grains 
of  sand  are  round,  or  almost  spherical.  This  is  true  only  in  a  limited  sense. 
There  are  some  round,  almost  spherical  grains  and  in  general  all  of  these  will 
be  retained  on  a  48-mesh  and  most  of  them  on  a  35-mesh  sieve.  Figure  16 
shows  a  number  of  these  large,  round  grains.  Aside  from  these,  however, 
most  of  the  grains  (figs.  16  and  17)  are  far  from  round  and  possess  angular 


SHAPE   OF   SAND   GRAINS 


45 


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PER    CENT 


Sample  No. 

7 — Ottawa  Silica  Co. 

9 — Standard   Silica  Co. 
13— U.  S.   Silica  Co. 
14 — Benson-Richards  Sand  Co. 
18 — Wedron  Silica  Co. 
25 — Bellrose  Sand  Co. 
33 — Utica  Fire  Sand  Co. 


Sample  No. 

36 — Higby-Reynolds  Silica  Co. 

40/41 — Amer.   Silica  Sand   Co. 

43 — Standard  Silica  Co. 

45 — South  Ottawa  Silica  Sand  Co. 

47— Ballou  White  Sand  Co. 

52 — National  Silica  Co. 

60/61 — Calhoun  County. 


Fig.  15.  Sieve  analyses  in  per  cent  by  weight  of  sand  from  exposures  of 
St.  Peter  sandstone  selected  to  show  the  variations  in  the  texture  of  the 
sandstone  in  different  localities. 


46  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

corners  or  surfaces  with  reentrant  faces.  From  an  examination  of  figures  16 
and  17  it  is  apparent  that  the  finer  grains  are  in  general  the  more  angular. 
Experiments  described  on  pages  148-151  demonstrate  the  fact  that  in  general 
the  finer  the  St.  Peter  sand,  the  more  angular  it  is. 

FROSTING 

The  St.  Peter  sand  has  commonly  been  described  as  consisting  of  frosted 
grains.  The  coarse  sand  is  frosted,  and  inasmuch  as  the  large  grains  are  the 
ones  commonly  observed  megascopically  or  with  a  hand  lens  the  statement 


Fig.  16.  St.  Peter  sand  showing  the  character  of  the  surface  and  shape  of  the 
grains.  The  grains  marked  A  and  B  show  respectively  a  pitted  grain  and 
the  surface  of  a  grain  which  has  fitted  into  a  pit.  Magnified  about  20  times. 
(Photograph  by  courtesy  of  U.  S.  Silica  Company.) 

is  correct  only  in  so  far  as  it  applies  to  them.  Figure  16  shows  some  coarse 
grains  which  have  frosted  surfaces.  Figure  17  shows  somewhat  more  clearly 
the  character  of  the  surface  of  the  medium-sized  grains.  It  is  apparent  from 
this  illustration  that  the  frosted  surface  of  the  medium-sized  sand  is  really 
formed  by  partial  frosting  with  much  chipping.  The  amount  of  frosting  in 
general  decreases  with  the  size  of  the  sand  grains.  The  frosted  surfaces  of 
the  coarser  grains  are  very  fine  grained. 


PITTING    OF    SAND    GRAINS 


47 


PITTING 


Manv  of  the  St.  Peter  grains  particularly  those  larger  than  65  mesh, 
are  conspicuously  pitted.  The  pits  are  of  two  types :  ( 1 )  those  in  frosted 
grains  and  (2)  those  in  grains  to  which  secondary  silica  has  been  added. 


PITS    IN    FROSTED    GRAINS 


These  pits  in  general  greatly  resemble  the  photographs  commonly  shown 
of  lunar  craters,  that  is  they  are  shallow  and  broad.  The  maximum  depth 
noted  was  about  0.1  millimeter.     The  width  varies  a  great  deal  according  to 


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J^W^U-  'a  ■  **  "T% 

iffl      ^PN,              JJfa^-    . 

KEyifc>"  **?§&:■  M       :    Jk  ''       L  t  -    IT         ^^wfc.        K  V 

Fig.  17.  Medium-sized  St.  Peter  sand.  These  grains  show  the  typical  shape  and 
surface  of  grains  of  this  size.  The  grain  marked  A  has  two  pits.  A  number 
of  other  grains  also  exhibit  depressions.  Magnified  about  35  times.  (Photo- 
graph by  courtesy  of  U.  S.  Silica  Company.) 

the  size  of  the  sand  grain.  The  maximum  noted  was  about  0.75  millimeter. 
The  floors  of  these  pits  have  slight  irregularities,  but  are  nearly  flat  in  gen- 
eral, and  some  have  frosted  surfaces  very  similar  to  the  frosted  surfaces  of 
the  sand  grains  themselves.  The  pits  have  probably  formed  at  the  contact  of 
two  sand  grains,  for  if  the  aggregates  of  two  or  more  grains  are  selected 
from  sand  and  washed  to  remove  the  clay,  it  will  be  found  in  a  large  per- 


48  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

centage  of  them  that  at  the  contact  of  any  two  grains  either  one  grain  is 
pitted  and  the  other  grain  fits  into  the  pit,  or  each  grain  shows  a  scar  which 
is  flat  and  the  two  scars  are  mutual  counterparts.  These  two  phenomena  are 
illustrated,  in  figure  16,  by  grains  A  and  B  respectively,  and  by  some  of  the 
grains  in  figure  17. 

The  method  of  formation  of  these  pits  is  not  clear,  but  it  appears  to  be 
solution.  It  was  thought  that  the  pits  might  have  been  formed  by  the  ac- 
cumulation of  a  thin  coating  of  silica  around  sand  grains  with  comparatively 
flat  surfaces  juxtaposed,  so  that  deposition  of  silica  would  go  on  around  the 
grains  but  would  not  materially  affect  the  flat  surfaces.  The  frosted  floors 
of  the  pits  seemed  to  lend  strength  to  this  view.  However,  thin  sections  of 
pitted  grains  failed  to  reveal  evidence  of  any  secondary  deposition  around  the 
sand  grain.  To  all  appearances  the  frosting  of  the  surfaces  of  the  sand  grains 
is  exclusively  a  superficial  phenomenon.  There  has  been  deposition  of  sec- 
ondary silica  in  the  St.  Peter  sand  locally,  but  the  tendency  is  to  reconstruct 
the  grains  so  as  to  form  crystals  or  crystal  terminations.  The  idea  of  solu- 
tion as  the  cause  for  this  pitting  therefore  seems  to  be  more  tenable.  It  is 
probable  that  these  pits  seem  more  common  on  the  larger  sand  grains  simply 
because  their  greater  size  makes  them  more  evident.  Solution  was  appar- 
ently differential  in  its  action,  for  not  all  large  grains  have  pits.  It  may  be 
that  the  etching  or  dissolving  solution  acted  principally  on  the  surface  of  the 
grains  in  the  vicinity  of  the  point  of  emergence  of  the  crystallographic  or 
vertical  axis,  along  which  solution  of  quartz  is  said  to  take  place  most  readily, 
and  that  pits  or  scars  were  well  developed  only  where  contact  of  this  axis 
and  some  other  flat-surfaced  grain  occurred.6  Apparently  the  formation  of 
pits  in  the  sand  grains  did  not  take  place  entirely  while  the  sand  was  a  part 
of  the  St.  Peter  sandstone,  for  numerous  grains  show  pits  which  are  rounded 
off  and  do  not  have  the  general  sharpness  of  rim  seen  in  the  pits  clearly  of 
St.  Peter  age. 

The  frosting  of  the  floors  of  the  pits  raises  a  question  not  only  as  to  its 
own  origin  but  as  to  the  origin  of  the  frosting  of  the  St.  Peter  grains  in 
general.  If  the  frosting  of  the  grains  in  general  is  due  to  solution  which  has 
taken  place  in  the  present  deposit  of  sand,  it  would  seem  that  the  large  and 
small  grains  alike  should  have  frosted  surfaces.  However,  it  has  been  pointed 
out  that  most  of  the  smaller  grains  are  but  slightly  frosted  and  some  not  at 
all.  It  would  appear,  therefore,  that  either  the  solution  which  frosted  the 
larger  grains  affected  them  at  some  other  site  of  deposition  than  the  present 
one  and  that  they  were  transported  to  their  present  location  in  such  a  fashion 
that  some  of  the  grain  aggregates  stuck  together,  or  the  frosting  is  due  to 
physical  rather  than  chemical  action.  The  evidence  seems  to  favor  the  phys- 
ical origin  but  the  origin  of  the  frosting  of  the  floors  of  the  pits,  though 
probably  due  to  etching,  is  not  definitely  known. 

fiPana,   TO.    S.,   and   Ford.   W.   E.,   A  textbook  of  mineralogy,   3d'  edition,   p.   191,   New 
York,   John    Wiley   &   Rons,    1922. 


SECONDARY    ENLARGEMENT   OF   SAND    GRAINS  49 

PITS   IN   GRAINS   WITH    ADDITIONS  OF   SECONDARY   SILICA 

The  addition  of  secondary  silica  to  the  grains  of  certain  portions  of  the 
St.  Peter  has  resulted  in  the  formation  of  euhedral  or  partly  euhedral  grains. 
At  the  point  of  contact  of  any  two  given  grains  it  is  common  to  find  pits 
whose  shape  is  dependent  principally  on  the  shape  of  the  grains  at  their  point 
of  contact.  The  bottoms  of  these  pits  are  commonly  frosted  like  other 
frosted  St.  Peter  grains.  This  type  of  pit  is  thought  to  have  been  formed  by 
the  aggregation  of  secondary  silica  about  grains  in  mutual  contact  but  not 
at  the  points  of  contiguity.  The  frosted  surfaces  of  the  floors  of  the  pits  are 
thought  to  be  the  frosted  surfaces  of  the  original  grains.  This  contention 
is  borne  out  by  thin-section  studies  of  grains  showing  pits  due  to  secondary 
deposition  of  silica. 

SECONDARY  ENLARGEMENT 

In  general,  enlargement  of  the  grains  of  the  St.  Peter  by  the  addition  of 
secondary  silica  is  common  in. outcrops  and  in  sand  from  wells  reaching  the 
St.  Peter  except  in  the  Ottawa-Utica  district  where  this  phenomenon  is 
restricted  primarily  to  weathered  deposits.  The  best  examples  of  this  phe- 
nomenon were  noted  in  the  sand  of  Calhoun  County  and  in  some  of  the 
outcrops  in  the  Oregon  district,  particularly  one  isolated  outcrop  of  very  red 
sandstone  in  the  SW.  ]/A  NE.  %  sec.  8,  T.  23  N.,  R.  10  E.,  about  a  quarter 
of  a  mile  northeast  of  the  quarry  of  the  National  Silica  Company.  The  sand 
in  Calhoun  County  contains  grains  which  have  been  added  to  until  they  are 
about  euhedral  as  well  as  many  small  and  perfect  crystals  of  quartz  which 
do  not  appear  to  be  secondarily  enlarged  quartz  grains.  Pitting  is  common 
in  the  larger  grains. 

In  the  locality  near  Oregon  the  grains  are  larger  and  the  amount  of  silica 
added  greater  than  in  Calhoun  County.  Most  of  the  grains  are  euhedral  and 
pitted.  The  deposit  is  very  red  as  a  result  of  the  presence  of  iron  oxide. 
The  secondary  silica  added  to  the  grains  is  stained  with  the  iron  oxide  whereas 
the  original  grain  is  free  from  this  coloring  material,  and  thus  there  is  a  very 
sharp  line  of  demarcation  between  the  original  grain  and  the  added  deposit. 

NUMBER  OF  GRAINS 

It  is  obvious  that  a  sieve  analysis  expressed  in  per  cent  by  weight  does 
not  give  information  as  to  the  number  of  grains  retained  on  each  sieve  except 
in  a  general  way.  Certain  uses  of  the  St.  Peter  demand  a  sand  which  consists 
essentially  of  fine  sand,  others  a  coarse  sand.  If,  therefore,  analysis  in  per 
cent  by  number  of  grains  were  available,  sand  might  be  selected  more  intelli- 
gently and  purchased  more  economically.  Aside  from  the  economic  value  of 
knowing  the  number  of  grains  indicated  in  a  sieve  analysis  by  weight,  these 
same  data  are  scientifically  interesting  because  they  throw  light  on  conditions 
of  sedimentation  and  the  physical  structure  of  the  St.  Peter. 


50  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

A  scrutiny  of  the  table  of  analyses  by  number  of  grains  (Table  11,  p. 
150)  shows  that  there  is  a  wide  variation  in  the  composition  of  the  sand  at 
the  various  quarries  but  suggests  that  in  general  the  quarries  located  near 
Ottawa  and  therefore  in  the  upper  part  of  the  St.  Peter  have  somewhat 
larger  per  cents  of  the  coarser  sand  than  do  those  near  Utica,  located  in  the 
middle  and  upper  middle  St.  Peter. 

Limestone  and  Dolomite  in  the  St.  Peter  Sandstone 

In  his  report  on  the  St.  Peter  sandstone  Dake7  shows  that  in  general  the 
St.  Peter  of  Canada,  Minnesota,  and  Wisconsin  is  free  from  calcarerous  or 
dolomitic  beds.  In  Illinois  and  Iowa  calcarerous  beds  are  present,  in  Missouri 
one  rather  persistent  limestone,  and  in  Arkansas  and  Oklahoma  generally  two 
persistent  limestone  beds. 

The  limestone  or  dolomitic  beds  occurring  in  Illinois  are  known  princi- 
pally from  well  logs.  In  the  Ottawa  district,  the  approximate  middle  portion 
of  the  formation  contains  beds  of  shaly  or  thin-bedded  sandstone  locally 
called  by  the  quarrymen  "magnesia  beds."  Samples  of  these  beds  contained 
no  magnesium  carbonate,  though  back  from  the  outcrop  where  weathering 
and  solution  have  not  been  so  active  these  beds  may  contain  that  compound. 
The  calcarerous  St.  Peter  in  Calhoun  County  and  near  Shirland  has  already 
been  mentioned.  However,  no  calcarerous  material  comparable  to  that  re- 
corded in  well  logs  in  Illinois  was  noted  in  outcrops  of  the  sandstone. 

The  most  reliable  data  on  the  presence  of  limestone  or  dolomite  in  the 
Illinois  St.  Peter  are  the  records  of  wells  at  Grays  Lake  and  Lake  Forest  in 
Lake  County.  Samples  were  obtained  from  these  wells  and  from  them  the 
St.  Peter  is  known  to  consist  of  20  feet  of  dolomite  overlain  by  30  feet  of 
sandstone  and  underlain  by  150  feet  of  sandstone  at  the  former  place  and 
at  the  latter  of  20  feet  of  dolomite  overlain  and  underlain  by  35  and  90  feet 
of  sandstone  respectively.  At  Area  (Mundelein)  in  the  same  county  the 
upper  50  feet  of  the  sandstone  is  said  to  be  calcarerous.  At  Mt.  Carmel  ceme- 
tery in  Cook  County  the  St.  Peter  is  120  feet  thick  and  the  upper  40  feet  is 
reported  as  calcarerous.  In  the  wells  in  Chicago  and  vicinity  .calcarerous  or 
dolomitic  sandstone  is  described  in  the  upper  St.  Peter  with  a  thickness 
varying  from  20  to  55  feet.  At  Quincy  in  Adams  County  a  well  records  23 
feet  of  limestone  overlain  by  11  feet  of  sandstone  and  underlain  by  96  feet 
of  sandstone. 

From  the  foregoing  data  it  seems  that  dolomite  or  limestone  beds  are 
present  locally  in  the  upper  part  of  the  St.  Peter  in  Illinois,  but  their  occur- 
rence suggests  that  the  beds  are  lenticular.  The  presence  of  calcarerous  or 
dolomitic  sandstone  at  the  top  of  the  St.  Peter  locally  also  seems  fairly  well 
established  though  the  possibility  that  the  carbonates  were  carried  down  the 


7Dake,   C.    L.,   The  problem   of  the   St.   Peter  sandstone:  Univ.   of  Missouri   School  of 
Minos  and  Metallurgy  Bull.,  technical  series,  vol.   6,  No.  1,  chapter  I,   1921. 


CLAY    IN    THE    SANDSTONE 


51 


drill    hole    from    the    overlying    limestone    and    dolomites    should    be   given 
consideration. 

Clay  in  the  St.  Peter  Sandstone 

character 

In  general  the  clay  of  the  St.  Peter  after  removal  from  the  sand  and 
concentration  in  sufficient  quantity  to  have  an  individual  color,  is  cream 
white,  varying  to  light  or  medium  yellow.  It  is  very  sticky  and  plastic.  When 
wetted  and  allowed  to  dry  it  forms  a  comparatively  hard  and  brittle  mass. 
The  analyses  in  Table  1  show  the  chemical  compositions  of  four  typical  clays. 


Table 

1. — Chemical  analyses  of  St.  Peter 

claysa 

United   States 

Silica 

Company 

Higby-Reynolds 
Silica  Company 
(Reynolds  west 
quarry) 

Ballou 

White  Sand 

Company 

National 

Silica 
Company 

L  ab.  No 

3.7  per  cent 
clay 

15366 

13 

48.8-8 

2.28 

33.43 

1.56 

1.06 

.78 

.04 

.34 

13.23 

1.65  per  cent 
clay 

15367 

38-39 

47.42 

2.32 

35.01 

1.26 

1.18 

.94 

.32 

.36 

13.20 

2.6  per 
cent  clay 

15368 

47 

48.92 

1.28 

33.71 

1.08 

1.06 

.88 

.04 

.34 

13.18 

1.33  per 
cent  clay 

15369 

51 

SiO  

53.58  • 

FeA 

Al  O 

2.93 
29.86 

2      3 

CaO 

.76 

MgO 

K  O 

.87 
.96 

Na20 

.04 

S0o 

.18 

3 

11.84 

Total 

101.60 

102.01 

100.49 

101.02 

oDate  reported  June  2,   1926  ;  analyst  J.  M.  Landgren 

OCCURRENCE 


The  clay  of  the  St.  Peter  occurs  principally  as  an  interstitial  filling 
between,  and  as  a  coating  on  the  sand  grains.  Locally  in  certain  zones  or 
beds,  commonly  not  over  5  feet  thick,  the  clay  content  is  greater  than  else- 
where, but  no  distinct  clavev  beds  or  lavers  were  noted  in  the  formation. 


52  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

DISTRIBUTION 

From  a  study  of  the  results  of  the  tests  for  clay  shown  in  Table  10,  p. 
148,  certain  very  interesting  data  are  brought  forth.  If  the  amount  of  clay 
is  plotted  on  a  map  it  becomes  apparent  that  the  outcrops  in  the  Ottawa- 
Utica  district  may  be  divided  into  three  groups  on  the  basis  of  clay  content. 
The  outcrops  in  the  first  group  are  east  of  a  line  running  north-south  through 
the  centers  of  sees.  9  and  16,  T.  33  N.,  R.  3  E.  They  have  a  low  clay 
content,  varying  from  0.72  to  1.60  per  cent  and  averaging  1.11  per  cent. 
The  second  group  lies  west  of  the  east  line  of  sec.  14,  T.  33  N.,  R.  2  E.,  and 
has  a  medium  clay  content  ranging  from  1.8  to  3.10  per  cent  and  averaging 
2.366  per  cent.  The  third  group,  the  one  having  the  high  clay  content,  lies 
between  the  other  two  geographically.  The  amount  of  clay  present  varies 
from  2.20  to  4.70  per  cent  and  averages  3.36  per  cent.  Although  these  divi- 
sions are  more  or  less  arbitrary  they  conform  in  a  general  way  to  the  distri- 
bution of  the  three  kinds  of  overburden  on  the  underlying  sandstone. 

In  the  area  of  low  clay  content,  the  sandstone  has  a  very  slight  over- 
burden consisting  of  river  silt  and  locally  of  limited  areas  of  Platteville- 
Galena  limestone  as  in  the  quarry  of  the  Standard  Silica  Company  (plant 
No.  2)  where  the  clay  content  is  highest  for  this  division.  The  sand  quarries 
in  this  area  are  located  in  the  Ottawa  platform.  The  unit  having  the  medium 
clay  content  is  in  the  area  near  Utica  where  Pennsylvania  strata  are  absent 
from  the  top  of  the  sandstone  and  are  replaced  by  glacial  drift  as  the  material 
superadjacent  to  the  sandstone.  The  area  of  high  clay  content  is  that  covered 
by  the  Pennsylvanian  clays  and  shale,  which  are  in  turn  overlain  by  glacial 
drift. 

ORIGIN 

Three  theories  for  the  origin  of  the  St.  Peter  clay  suggest  themselves: 
(1)  that  the  clay  is  primary;  (2)  that  the  clay  is  secondary;  and  (3)  that 
some  of  the  clay  is  secondary  and  some  primary.  The  primary  origin  implies 
•  that  the  clay  was  deposited  at  the  same  time  as  the  sand  itself,  the  secondary 
origin  that  it  has  been  introduced  into  the  sandstone  since  its  deposition,  and 
the  combination  of  primary  and  secondary  origin  that  the  clay  as  now  found 
is  the  result  of  both  modes  of  accumulation. 

One  of  the  most  striking  things  shown  by  the  table  of  chemical  analyses 
of  the  St.  Peter  clays  (page  51)  is  the  similarity  of  the  analyses.  The 
samples  tested  were  selected  to  represent  the  St.  Peter  in  various  regions 
where  it  outcrops  and  is  worked  commercially  and  are  therefore  widely  spaced 
as  sbown  by  the  map  of  the  St.  Peter  outcrops  (PI.  I,  p.  14).  They  also 
represent  different  parts  of  the  formation  vertically.  If  the  clays  were  sec- 
ondarily introduced  into  the  sandstone  it  would  seem  logical  to  expect  a 
difference  in  the  character  of  the  clay  in  different  geographic  areas.    The  fact 


CLAY    IN    THE    SANDSTONE  5o 

that  the  clays  are  so  very  nearly  alike  as  to  chemical  analysis,  areally  and  with 
respect  to  the  formation  as  a  whole,  suggests  that  they  have  been  introduced 
into  the  sandstone  by  some  agency  capable  of  depositing  clay  of  the  same  sort 
at  about  the  same  time  over  a  wide  area.  This  requirement  seems  to  be 
satisfied  by  the  primary  deposition,  in  the  St.  Peter  sea,  of  clay  derived  from 
essentially  the  same  source  throughout  St.  Peter  time.  The  freedom  of  the 
sandstone  from  beds  of  clay  show  that  the  St.  Peter  sea  was  clear  and  that 
the  comparatively  small  amount  of  clay  deposited  was  probably  mechanically 
entrapped  during  the  deposition  of  the  sand. 

According  to  the  foregoing  statement  the  St.  Peter  should  contain  about 
the  same  amount  of  clay  throughout  its  areal  extent.  It  has  been  pointed 
out,  however,  that  this  is  not  the  case,  and  in  this  connection  should  be  noted 
the  distinct  relation  between  the  perviousness  of  the  overburden  to  ground 
water  and  the  clay  content  of  the  sandstone  above  ground-water  level.  Where 
the  overburden  is  Pennsylvanian  clay  and  shale,  the  clay  content  of  the  sand- 
stone is  the  highest,  presumably  because  these  beds  are  highly  impervious  to 
water  and  therefore  do  not  permit  the  ready  entrance  of  water  into  the  sand- 
stone, thereby  defeating  downward  concentration  of  the  interstitial  clay  to  a 
zone  at  or  below  the  ground-water  level.  Where  the  overburden  is  a  thin 
covering  of  silt  the  entrance  of  ground  water  is  not  greatly  hindered  and 
downward  concentration  of  clay  is  readily  accomplished.  The  permeability 
of  glacial  drift  would  be  intermediate  between  that  of  the  Pennsylvanian  beds 
and  that  of  silt.  Fluctuations  of  the  level  of  ground  water  might  also  cause 
downward  concentration  of  the  clay. 

Downward  concentration  of  materials  by  ground  water  is  evidenced  by 
the  bands  containing  organic  material  found  in  a  number  of  the  quarries  in 
the  Ottawa  platform,  especially  in  the  quarry  of  the  Standard  Silica  Com- 
pany. These  materials  have  been  carried  to  a  depth  of  at  least  12  feet  since 
Illinois  River  ceased  to  erode  actively  the  rock  terraces  in  its  valley  and  since 
organic  material  became  an  important  constituent  of  the  soil  overlying  the 
sandstone  in  these  terraces.  Another  phenomenon  thought  to  indicate  concen- 
tration of  clay  by  ground  water  is  the  commonly  joint  occurrence  of  high  clay 
and  high  iron  content  in  the  same  bed  of  sandstone.  In  the  quarries  which 
reach  the  depth  of  ground-water  level  it  is  very  common  to  find  the  bottom 
beds  much  higher  in  clay  than  those  well  above  water  level.  These  former 
beds  are  often  termed  "magnesia"  layers,  because  of  the  high  percentage  of 
fine  sand  and  clay  they  contain. 

The  chief  argument  for  the  secondary  origin  of  the  clay  of  the  St.  Peter 
is  its  distribution  in  the  fashion  which  would  be  expected  from  the  transpor- 
tation of  clay  by  descending  ground  water  and  its  concentration  in  zones  at 
or  just  above  temporary  ground-water  tables.  The  absence  of  conspicuous 
beds  of  clay  also  argues  for  this  origin.  What  most  seriously  opposes  sec- 
ondary origin  of  the  clays  is  that  if  they  came  from  the  overburden  as  it  is 


54  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

today,  they  should  not,  and  probably  would  not,  have  the  similar  chemical 
compositions  which  the  analyses  indicate,  unless  practically  all  of  the  clay  came 
into  the  sandstone  from  the  Pennsylvanian  strata  before  erosion  removed 
parts  of  them.  The  imperviousness  of  the  fire  clay  and  shales  on  the  sand- 
stone suggests  that  no  great  amount  of  ground  water  would  permeate  them 
at  one  time,  but  over  a  long  period  of  time  it  is  possible  that  sufficient  clay 
might  be  carried  down  from  the  fire  clay  to  give  the  sandstone  its  present  clay 
content.  This  would  not,  however,  account  for  the  similarity  of  the  clay  of 
the  Oregon-Dixon  area,  where  the  overburden  is  limestone  or  drift,  to  the 
clay  of  the  La  Salle  area. 

It  would  seem  that  to  account  completely  for  the  clay  in  the  St.  Peter  a 
combination  of  primary  and  secondary  origins  should  be  postulated.  How- 
ever, it  is  thought  that  the  bulk  of  the  clay  in  the  formation  is  probably 
primary,  but  that  its  composition  and  distribution  have  been  modified  by 
secondary  additions  and  by  re-distribution. 

Iron  in  the  St.  Peter  Sandstone 

In  general,  the  amount  of  iron  contained  by  the  St.  Peter  sandstone  is 
relatively  low  (Table  2).  Some  very  red  and  decidedly  green  sands  have 
been  analyzed  and  found  to  contain  only  one-half  of  one  per  cent  of  iron 
oxide  (Fe203).  The  deepest  yellow  sand  obtainable  contained  less  than  0.3 
per  cent  iron  oxide.  These  analyses  do  not  include  the  amount  of  iron  in  the 
ramifying,  vein-like  bands  of  red  iron  oxide  and  silica  which  occur  locally  in 
the  sandstone.  Iron,  Recurring  principally  as  the  sulphide,  is  present  in  smaller 
amounts  in  the  white  sandstone  than  in  the  colored  sand.  The  total  impurities 
in  the  white  sand  rarely  exceed  three  per  cent  and  are  chiefly  clay. 

OCCURRENCE 

Except  where  disseminated  as  marcasite  masses  and  marcasite  vein  fill- 
ings, the  iron  compounds  in  the  St.  Peter  occur  as  a  coating  on  the  sand 
grains,  or  as  a  constituent  of  the  interstitial  clay  or  in  both  ways.  In  this 
bulletin  the  term  "iron  bands"  is  used  for  convenience  but  with  the  specific 
understanding  that  such  bands  are  simply  zones  in  the  sandstone  in  which  iron 
compounds  occur  as  a  coating  on  the  sand  or  as  interstitial  material.  Of  the 
yellow,  red,  and  green  iron  oxides,  the  last  two  are  comparatively  uncommon. 
Green  sand  was  found  near  Rockford  and  Oregon,  associated  with  the  upper 
and  basal  beds  of  the  formation.  The  largest  exposure  of  green  sandstone 
noted  was  at  Green  Rock  in  NW.  *4  sec.  11,  T.  22  N.,  R.  10  E.,  where  about 
20  feet  of  interbedded  green  and  white  sand  is  exposed.  The  only  observed 
extensive  bodies  of  sand  colored  by  the  red  oxides  were  found  near  Oregon 
and  in  Calhoun  County.  Elsewhere  the  red  sand  is  found  as  part  of  the 
eement-forming,  ramifying,  vein-like  bands  through  the  sandstone  or  as  local 


IRON    IN    THE    SANDSTONE 


55 


Table  2. — Iron  in  the  St.  Peter  sandstone 


Sample  No. 


A 
B 
11 
14 
21 
24 
25 
26 
27 
33 
34 
35 
38 
40 
42 
45 
51 


Quarry   or   outcrop 


Per  cent  iron 
oxide    (Fe203) 


Red  St.  Peter   sand - 

Green  St.  Peter  sand 

Ottawa   Silica   Molding  Sand   Company 

Benson  Richards  Sand   Company 

Wedron  Silica  Company 

National  Plate  Glass  Company  (new  pit) 

Bell  rose  Sand  Company 

Illinois  Valley  Silica   Company 

Standard  Silica  Company 

Standard  Silica  Company   (Plant  No.  3)... 

Federal  Silica  Mines 

Federal  Silica  Mines 


Higby-Reynolds   Silica   Company    (Reynolds  west 

quarry)      

American  Silica  Sand  Company-' 


Rock  Island  Sand  Company 

South  Ottawa  Sand  Company- 
National  Silica  Company 


.51 
.51 

.30 
.34 
.20 
.32 
.31 
.35 
.27 
.15 
.23 
.25 
.12 
.22 
.43 
.10 
.09 


irregular  masses  which  give  the  exposures  of  the  sandstone  a  blotchy  appear- 
ance. The  yellow  oxide  is  by  far  the  most  common.  It  occurs  in  four  prin- 
cipal ways: 

( 1 )  As  more  or  less  regular  bands  from  a  fraction  of  an  inch  to  about 
a  foot  thick.  In  some  places  the  oxide  is  found  in  porous  beds  of  sandstone 
which  are  underlain  by  beds  containing  a  high  percentage  of  very  fine  sand. 
In  other  places  these  bands  are  found  in  homogeneous  beds  without  any  fixed 
vertical  position  with  reference  to  the  beds  as  a  whole.  Screen  analyses  of  the 
sand  above  and  below  these  bands  and  of  the  sand  composing  them  show 
practically  no  difference  in  texture. 

(2)  As  irregular,  ramifying  bands.  These  occur  along  joint  planes  and 
also  in  homogeneous  beds  of  sandstone  which  they  penetrate  at  random.  Sieve 
analyses  of  the  sand  adjacent  to  and  composing  these  bands  show  no  signifi- 
cant difference  in  texture. 


56  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

(3)  As  concentric  bands  from  y%  to  ?4  mcn  thick  around  a  center  of 
sand  held  together  by  pyrite,  of  sand  held  together  by  a  deposit  of  very  brown 
iron  oxide,  or  of  pure  white  sand.  The  resulting  mass  of  iron-cemented  sand 
is  roughly  spherical  and  concretionary.  These  spherical  masses  occur  in  zones, 
most  commonly  in  beds  of  medium  or  coarse  sand,  and  also  along  joint  faces. 
Few  of  the  entire  nodules  are  over  4  inches  in  diameter ;  they  are  commonly 
between  l1^  and  2  inches  in  diameter. 

(4)  As  irregular  masses  ranging  in  size  from  about  }i  inch 'to  several 
feet.  In  places  the  sandstone  is  literally  peppered  with  the  smaller  deposits  of 
the  yellow  oxide. 

The  iron  sulphide  in  the  St.  Peter  occurs  as  both  marcasite  and  pyrite, 
though  the  former  predominates,  in  three  principal  ways : 

(1)  As  disseminated  interstitial  masses.  These  are  most  commonly 
found  in  strata  of  medium  or  coarse  sand,  and  occur  in  zones  and  in  deposits 
distributed  through  what  are  probably  individual  beds.  The  disseminated 
marcasite  is  found  almost  exclusively  in  that  part  of  the  St.  Peter  which  con- 
stitutes the  rock  terraces  of  Illinois  and  Fox  rivers.  In  one  outcrop  attenuated 
rows  of  interstitial  marcasite  grains  were  noted  following  the  cross-bedding 
of  the  sandstone. 

(2)  As  a  cement  binding  sand  together  in  the  form  of  nodules.  These 
marcasite-sand  nodules  are  commonly  round  and  vary  from  y%  inch  to  3 
inches  in  diameter.  Some  are  surrounded  by  concentric  bands  of  brown  and 
yellow  sand,  and  others  are  sharply  defined  from  the  sand  matrix  without  any 
discoloration  at  the  periphery. 

(3)  As  a  joint  filling.  The  best  type  of  this  occurrence  of  marcasite 
was  noted  at  Wedron  where  the  removal  of  the  sandstone  from  one  side  of  a 
joint  had  left  the  filling  as  a  scale  about  y^  inch  thick  over  the  lower  20  feet 
of  a  65-foot  face  with  a  linear  extent  of  about  50  feet  (fig.  6). 

ORIGIN 

As  stated,  all  the  iron  minerals  so  far  described  occur  not  as  individual 
grains  but  as  an  interstitial  filling  or  as  a  coating  on  sand  grains.  They  cannot, 
therefore,  be  considered  primary  in  the  same  sense  as  the  zircon,  rutile,  and 
tourmaline  found  with  the  sand,  but  may  represent  iron  deposited  contempo- 
raneously with  the  accumulation  of  the  St.  Peter  sand.  The  only  iron-bearing 
mineral  noted  in  the  St.  Peter  which  is  certainly  primary  is  black  tourmaline. 
The  number  of  grains  of  this  mineral  is  proportionately  very  small  and  as  the 
grains  show  no  evidence  of  solution,  they  do  not  seem  likely  sources  for  any 
considerable  amount  of  secondary  iron  in  the  sandstone. 

It  is  thought  that  the  present  deposition  by  springs  of  hydrated  iron 
oxides  in  the  St.  Peter  sandstone  and  the  occurrence  of  joint  fillings  of  mar- 
casite, obviously  deposited  by  ground  waters,  together  with  the  lack  of  any 


IRON    IN    THE    SANDSTONE  57 

consistent  relation  between  the  iron  present  and  stratification,  and  the  absence 
of  horizontal  deposits  of  the  marcasite,  seem  to  favor  the  secondary  origin  of 
the  iron  in  the  St.  Peter. 

SOURCE   AND    MODE   OF    ACCUMULATION 

In  this  discussion  remarks  will  be  confined  chiefly  to  the  Ottawa-Utica 
area  in  northern  Illinois  because  this  region  contains  the  most  extensive  ex- 
posures of  the  St.  Peter  in  the  State.  It  is  thought,  however,  that  the  origin 
of  the  iron  in  this  region,  if  correctly  ascribed,  should  give  a  key  to  the  origin 
of  the  iron  elsewhere,  modified  perhaps  by  local  conditions. 

In  the  rock  terrace  near  Ottawa  the  iron  in  the  sandstone  occurs  princi- 
pally as  interstitial  marcasite  and  as  limonite  mixed  with  the  interstitial  clay. 
The  discloration  of  the  sandstone  is,  in  general,  slight.  The  overburden  is 
commonly  either  river  alluvium  or  Platteville-Galena  limestone.  From  Ottawa 
west  for  about  A-]/2  miles  the  sand  quarried  for  molding  sand  from  the  river 
bluffs  is  strikingly  yellow,  especially  in  the  upper  portion  of  the  exposures. 
The  iron  occurs  principally  as  limonite  in  horizontal  and  ramifying  bands  and 
also  as  small  blotches  speckling  the  sandstone.  Interstitial  marcasite  is  also 
present  usually  associated  with  annular  deposits  of  yellow  oxides  around  the 
marcasite  centers.  The  overburden  on  this  sandstone  consists  in  ascending 
order  of  fire  clay — commonly  containing  marcasite  or  pyrite  nodules  and  con- 
cretions— coal,  shale  and  glacial  drift.  Near  Utica  the  sandstone  taken  as  a 
whole  is  buff  colored,  though  in  the  upper  part  of  the  exposures  yellow  bands 
of  sand  are  common.  Interstitial  marcasite  is  relatively  common  with  yellow 
bands  surrounding  the  marcasite  core.  The  overburden  consists  of  glacial 
drift. 

There  are,  therefore,  three  different  types  of  sand  in  this  Ottawa-Utica 
district,  the  white  (or  nearly  white),  the  yellow,  and  the  buff,  and  each  type 
has  a  different  overburden.  The  topographic  position  of  the  yellow  and  buff 
sands  is  the  same.  The  deposits  in  the  rock  terrace  near  Ottawa  are  topo- 
graphically lower  than  those  in  the  bluff.  It  seems  reasonable  to  conclude, 
therefore,  that  the  overburden  has  been  to  a  large  extent  the  source  of  the  iron 
contained  in  the  sandstone  and  that  the  variation  in  the  intensity  of  the  colora- 
tion caused  by  the  iron  hydroxide,  or  the  amount  of  the  oxide  present,  reflects, 
more  or  less  directly,  the  amount  of  ferruginous  material  available  to  ground 
water  in  the  overburden.  In  all  three  types  of  sand  the  amount  of  marcasite 
present  is  thought  to  be  about  the  same,  but  in  the  quarries  in  the  rock  terrace 
near  Ottawa,  the  oxidation  of  the  marcasite  to  the  yellow  oxide  is  much  less 
marked  than  in  the  molding  sand  quarries  in  the  bluff  farther  west. 

Inasmuch  as  springs  issuing  from  the  St.  Peter  in  the  base  of  some  of 
the  pit  quarries  which  have  been  deepened  to  ground-water  level,  are  deposit- 
ing iron  hydroxide  and  producing  regular  bands  of  yellow  sand  as  well  as 
irregular  limonite-stained  masses  in  the  sand  at  or  near  ground-water  level,  it 


58  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

seems  logical  to  conclude  that  this  type  of  deposition  may  be  responsible  for 
the  bands  and  irregularly  stained  sand  masses  where  they  are  colored  by 
limonite.  The  fluctuation  in  the  water  table  and  the  causes  thereof  are  a 
problem  in  themselves,  but  it  may  be  suggested  that  such  fluctuations  were 
related  to  variations  in  the  volume  of  water  carried  by  Illinois  River  during 
glacial,  interglacial,  and  post-glacial  times. 

The  marcasite  with  its  associated  annular  deposits  of  yellow  oxides 
admits  of  three  possible  modes  of  origin:  (1)  The  marcasite  is  primary,  and 
the  rings  of  yellow  oxide  surrounding  it  are  the  result  of  its  oxidation;  (2) 
the  marcasite  is  secondary  and  the  yellow  rings  around  the  central  mass  are 
due  to  its  oxidation;  (3)  the  core  has  been  formed  by  the  reduction  of  the 
annular  yellow  oxide  and  the  inward  concentration  of  the  reduced  product. 

The  first  mode  of  origin  is  self-explanatory.  If  the  second  mode  of  origin 
was  the  case  the  marcasite  has  probably  been  precipitated  from  solutions  in 
the  sandstone  and  hydrogen  sulphide  which  is  common  in  some  waters  of  the 
St.  Peter  may  be  responsible  for  the  precipitation.  If  the  third  mode  of  origin 
was  the  case  it  seems  that  the  process  of  forming  iron  sulphide  from  the 
yellow  oxide  has  not  been  active  for  some  time  except  perhaps  locally,  for  the 
St.  Peter  sandstone,  especially  in  the  Illinois  River  bluff,  has  probably  been 
above  ground-water  level  and  subject  to  oxidation  most  of  the  time  since  the 
Wisconsin  glaciation. 

The  data  available  seem  to  favor  the  second  mode  of  origin. 

Concerning  the  ramifying  bands  of  red  and  yellow  iron  oxides  which 
penetrate  the  sandstone,  in  many  places,  it  is  tentatively  suggested  that  these 
bands  may  represent  the  course  of  solutions  descending  from  concentrating 
areas  such  as  depressions  or  basins  in  the  top  of  the  sandstone,  or  similar  areas 
in  the  top  of  a  relatively  impervious  bed  in  the  sandstone  overlain  by  a  porous 
stratum.  This  condition  of  maximum  iron  content  below  depressions  in  the 
top  of  the  sandstone  was  strikingly  shown  in  the  quarry  at  Oregon.  If  these 
downward-moving  waters  were  charged  with  iron  oxides  in  suspension  as 
finely  divided  solids  or  colloids,  they  might  follow  an  irregular  course  through 
the  sandstone ;  the  course  would  be  influenced  by  minor  differences  in  the 
porosity  of  the  sand  caused  by  the  size  of  the  sand  grains  or  by  the  amount 
of  interstitial  clay  present.  As  a  result  of  retarded  circulation  the  waters 
would  leave  along  the  edge  of  their  zone  of  descent  a  coating  of  iron  oxide 
which  would  serve  to  delimit  the  margin  and  circumscribe  the  width  of  the 
hand.  In  the  center  the  movement  of  the  w'ater  would  keep  the  channel  clean 
for  a  time.  As  the  channels  become  filled  or  clogged  by  deposits  of  iron  from 
the  water,  the  descending  fluid  would  be  forced  to  back  up  or  break  through 
the  surrounding  deposit  and  seek  new  ways  of  descent.  Repeated  clogging  of 
a  delimited  path  of  descent  and  the  development  of  new  paths  together  with 
variations  in  the  porosity  of  the  sandstone  may  be  the  key  to  an  explanation 
<»f  ibis  phenomenon. 


HEAVY    MINERALS    IN    THE    SANDSTONE  59 

Heavy  Minerals  in  the  St.  Peter  Sandstone 

In  view  of  its  high  quartz  content  and  the  amount  of  clay  present,  it  is 
obvious  that  the  St.  Peter  cannot  contain  very  large  amounts  of  heavy  min- 
erals. Separation  of  the  heavy  minerals  from  the  quartz  sand  has  commonly 
been  effected  by  the  use  of  liquids  of  such  gravity  as  to  float  the  quartz  and 
allow  the  other,  heavier  constituents  to  sink.  In  view  of  the  inadaptability  of 
this  method  to  handling  of  large  quantities  of  sand  and  obtaining  representa- 
tive collections  of  heavy  minerals  from  the  St.  Peter  sand,  samples  of  about  20 
pounds  each  were  run  over  a  Wilfley  jig  table  so  regulated  as  to  give  a  separa- 
tion of  the  quartz  sand  and  the  minerals  of  greater  specific  gravity.8  Each 
sample  was  run  over  the  table  three  times  and  the  crop  from  the  table  further 
concentrated  in  bromoform. 

As  Table  3  shows,  the  principal  heavy  minerals  occurring  in  the  St.  Peter 
sandstone  are  zircon,  tourmaline,  anatase  (octahedrite),  and,  in  lesser  amounts, 
pyrite,  marcasite,  limonite,  spinel,  and  garnet. 

Zircon  is  the  most  common  heavy  mineral  present.  The  grains  vary 
greatly  in  size  and  range  from  very  minute  to  comparatively  large  grains 
about  a  millimeter  in  maximum  dimension.  Most  of  the  grains  are  of  the 
elongate  rather  than  of  the  stumpy  type,  and  are,  almost  without  exception, 
rounded.  Some  are  so  rounded  as  to  be  roughly  cylindrical  in  shape ;  others 
are  less  rounded  and  the  original  larger  faces  are  still  recognizable.  Most  of 
the  larger  grains  contain  inclusions.  The  grains  are  in  general  white,  though 
a  few  very  light  pink  and  yellow  grains  were  noted. 

The  tourmaline  grains  are  in  general  very  well  rounded;  some  of  the 
black  grains  are  nearly  spherical.  There  are,  however,  a  few  euhedral  grains, 
mostly  yellow  or  brown.  Black  and  brown  tourmaline  is  by  far  the  most 
common.  Yellow,  purplish-brown,  reddish-brown,  and  orange-red  grains  are, 
however,  not  uncommon  and  there  are  also  a  few  green  and  blue  grains. 

The  anatase  occurs  mainly  as  flat,  tabular,  octahedral,  orange  or  yellow 
grains.  The  grains  are  euhedral  and  show  no  signs  of  wear  other  than  break- 
age by  fracturing. 

The  marcasite  and  pyrite  occur  chiefly  as  remnants  of  interstitial  mate- 
rials. There  are,  however,  a  number  of  octahedrons  and  cubes  of  pyrite  and 
crystalline  aggregates  of  marcasite.  The  limonite  occurs  in  the  same  general 
shape  and  form  as  the  iron  minerals  already  mentioned  and  much  of  it  pre- 
serves the  crystal  form  of  the  mineral  after  which  it  is  a  pseudomorph. 

The  spinel  grains'  are  well  rounded  and  green.  They  are  probably  ceylon- 
ite.  The  few  garnets  noted  were  light  green  and  rounded.  The  mineral 
thought  to  be  epidote  was  angular. 


8The  author  is  indebted  to  Professor  A.  E3.  Drucker  of  the  Dept.  of  Mining 
Engineering  of  the  "University  of  Illinois  for  his  assistance  and  cooperation  in  this 
separation. 


60  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

Table   3. — Heavy  mineral  content   of  the  St.  Peter  sandstone 


Estimated  per  cent  of 
major  constituents 

"a, 

CO 

a 
0 

o 

"H, 

u 
>> 

en 
03 
o 
u 
a 

'5 

o 

£ 
13 

Grams  of 
heavy  min- 

Sample 
No. 

Zircon 

Tour- 
maline 

Anatase 

(octahe- 

drite) 

erals    in 

10  lbs.  of 

St.  Peter 

sand 

1 

45 

45 

10 

R 

R 

R 

0.07 

8 

55 

45 

R 

R 

C 

1.62 

9 

55 

45 

R 

* 

* 

A 

1.26 

11 

50 

50 

R 

* 

R 

1.51 

13 

65 

35 

R 

C* 

C 

1.27 

18 

45 

55 

C 

R 

c 

1.33 

25 

65 

35 

R 

R 

R 

3.19 

33 

50 

50 

R 

2.40 

36 

80 

20 

R 

R 

2.60 

43 

50 

45 

5 

R 

C* 

C* 

C 

1.14 

45 

50 

50 

R 

R 

R* 

* 

R 

0.95 

47 

70 

30 

R 

R 

2.78 

51 

35 

30 

35 

3.60 

54 

50 

50 

R 

R 

R* 

* 

R 

1.93 

60-61 

30 

70 

R 

R* 

* 

R 

0.18 

R — rare  C — common  A— abundant 

The  asterisks  in  the  pyrite  and  marcasite   columns  indicate  from  which  of  the  two 
minerals  the  limonite  has  probably  been  derived. 

In  addition  to  the  above  mentioned  minerals  there  are  a  number  of  grains 
which  are  translucent  or  opaque,  white,  gray,  brown,  red  or  yellow,  but  which 
were  not  definitely  identified.  All  have  very  smooth  and  shiny  surfaces  in 
contrast  with  the  frosted  surfaces  of  the  other  grains.  It  is  thought  that  the 
white  and  gray  grains  are  probably  chalcedony,  chert  or  agate.  The  other 
grains  are  very  easily  crushed  to  a  powder  and  are  thought  to  be  masses  of 
clay  with  a  ferruginous  cement. 

The  surfaces  of  the  tourmaline,  zircon,  spinel  and  garnet  grains  are  in 
general  frosted.  The  frosting  is  usually  similar  to  that  on  the  St.  Peter 
grains,  but  the  surfaces  of  some  of  the  grains  are  covered  with  minute  chip 
marks.  Some  of  the  tourmaline  grains  show  irregular  pits  and  grooves, 
through  which  the  unfrosted  mineral  shows  very  clearly.    It  is  also  not  tin- 


HEAVY    MINERALS    IN    THE    SANDSTONE 


61 


common  to  find  some  of  the  black  tourmaline  grains  with  one  side  beveled  to 
a  very  flat,  even  surface. 

Aside  from  the  minerals  listed,  mica  was  noted  in  the  basal  St.  Peter  in 
the  Oregon-Dixon  area.  Because  of  its  flaky  character,  any  of  this  mineral 
which  might  be  present  in  the  samples  would  be  lost  during  the  concentration 
on  the  Wilfley  table. 

The  size  of  the  heavy  mineral  grains  is  shown  in  Table  4.  In  general  the 
heavy  grains  are  small  compared  with  the  quartz  grains  composing  the  St. 
Peter  sand.  It  is  also  of  interest  that,  comparatively,  the  tourmaline  grains 
are  the  largest,  the  zircon  grains  of  medium  size,  and  the  anatase  grains 
smallest. 


Table  4.- 

-Size  of  heavy  mineral  grains 

Sieves 

Sieve  openings 
Millimeters 

Per  cent 
retained 

Mineralogical  composition 

Thr'gh 

On 

of  sand  retained  a 

48 

65 

.295 

.208 

0.4 

Principally   black    and   brown   tourmaline 

65 

100 

.208 

.147 

11.7 

Black  and  brown  tourmaline  about  90  per 
cent,  zircon   about  10  per  cent 

100 

150 

.147 

.104 

18.0 

Principally  tourmaline  and  zircon  in  about 
equal  amounts,  and  spinel  in  minor 
amounts 

150 

200 

.104 

.074 

26.6 

Zircon  about  70  per  cent,  tourmaline  about 
30  per  cent,  minor  amounts  of  spinel 

200 

270 

.074 

.053 

19.0 

Zircon  about  85  per  cent,  tourmaline  about 
10  per  cent,   anatase  about  5  per  cent 

Pan 

Less  th; 

in  .053 

24.3 

Zircon  about  85  per  cent,  tourmaline  about 
10  per  cent,  anatase  about  5  per  cent 

aPyrite,    marcasite    and    limonite    in    minor    amounts    are    present    in    all    the    samples, 
though  principally  in   the  larger  sieve  sizes. 

Of  the  grains  identified  from  the  St.  Peter  the  zircon,  tourmaline,  garnet, 
spinel,  and  epidote  are  thought  to  be  primary.  The  pyrite,  marcasite,  limo- 
nite, and  anatase  are  thought  to  be  secondary. 

The  weights  of  heavy  mineral  grains  present  in  the  samples  are  shown  in 
Table  3.  These  figures  are  influenced  to  some  extent  by  the  differences  in 
specific  gravity  of  the  predominant  minerals,  but  they  give  approximately  the 
quantity  of  heavy  grains  present  in  a  unit  weight  of  sand.  It  is  of  interest 
that  the  samples  of  sand  from  quarries  in  the  rock  terrace  near  Ottawa,  Sam- 
ples 1,  8,  9,  13,  43,  and  45,  are  comparatively  low  in  heavy-mineral  content, 
whereas  the  samples  from  the  Illinois  River  bluff  west  of  Twin  Bluffs,  Nos. 
25,  33,  and  36,  are  comparatively  high.  Sample  11  from  Buffalo  Rock  is  an 
exception  to  these  general  relations,  for  it  has  a  low  mineral  content  although 


62  THE   ST.   PETER   SANDSTONE   OF   ILLINOIS 

it  would  normally  be  expected  to  resemble  the  river  bluff  samples  rather  than 
the  rock  terrace  samples  in  this  respect.  Sample  18  from  Wedron  coincides 
with  the  samples  from  the  rock  terrace.  The  differences  in  the  heavy-mineral 
content  are  thought  to  be  due  to  horizontal  rather  than  vertical  variations  in 
the  quantity  of  the  minerals  present. 


CHAPTER    IV— THE    QUARRYING    AND    PREPARATION    OF 

ST.  PETER   SAND 

Introduction 

The  various  grades  of  St.  Peter  sand  produced  commercially  in  Illinois 
may  be  combined  into  two  principal  groups,  washed  sand  and  crude  sand.  As 
the  name  implies,  the  former  is  washed  before  it  is  sold,  and  its  quarrying  and 
preparation  is  a  very  different  process  from  that  employed  with  the  crude 
sand  which  is  commonly  sold  without  preparation  other  than  crushing.  The 
quarrying  and  preparation  of  these  two  classes  of  sand  will,  therefore,  be 
discussed  separately. 

Washed  Sand 

general  statement 

Washed  St.  Peter  sand  has  a  multiplicity  of  uses  which  are  described  in 
Chapter  V.  This  type  of  sand  is  often  spoken  of  as  glass  sand,  because  large 
amounts  of  it  are  sold  for  making  high-grade  glass.  It  also  finds  wide  use  as 
sand-blast  sand,  filter  sand,  engine  sand,  and  grinding  and  polishing  sand.  In 
fact,  whenever  a  silica  sand  of  highest  purity  is  desired,  the  St.  Peter  may 
be  used. 

In  general  only  sand  which  is  initially  freer  from  iron  than  the  crude 
sand  sold  for  steel  molding  is  washed  because,  though  the  clay  can  be  removed 
during  the  washing  process,  the  iron  coating  the  sand  grains  is  much  more 
difficult  to  eliminate. 

The  quarries  producing  washed  sand  are  located  with  a  few  exceptions  in 
terraces  along  the  Illinois  or  Fox  rivers.  The  Ottawa,  Standard  (Plants  1 
and  2),  and  United  States  Silica  Companies  are  located  in  the  Ottawa  terrace, 
a  rock  terrace  in  the  valley  of  Illinois  River.  The  Wedron  Silica  Company 
and  Ballou  White  Sand  Company  are  located  in  rock  terraces  along  the  Fox. 
The  two  remaining  quarries,  Higby-Reynolds  and  the  National  Silica  Com- 
panies, are  located  respectively  in  the  bluff  of  Illinois  River  and  in  a  rock  hill 
not  related  to  any  large  stream. 

TYPES  OF  QUARRIES 

There  are  two  principal  types  of  quarries  from  which  washed  sand  is 
produced,  namely  pit  and  bluff  quarries.  Quarries  of  the  first  type  are  those 
which  have  been  sunk  in  a  comparatively  level  original  surface.  The  bluff 
quarries  are  those  which  have  been  developed  by  working  back  into  a  bluff  or 

63 


64 


THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


QUARRYING 


65 


cliff  of  rock.   The  majority  of  the  washed  sand  quarries  are  pit  quarries  (figs. 
18  and  19). 

OVERBURDEN  AND  ITS  REMOVAL 

In  most  quarries  the  overburden  on  the  sandstone  quarried  for  washed 
sand  is  unconsolidated  material,  silt,  sand,  gravel  or  glacial  drift.  The  average 
thickness  varies  from  6  inches  to  10  feet.  At  the  quarries  of  the  United 
States  Silica  Company  and  Standard  Silica  Company  (plant  No.  2),  however, 
there  are  local  areas  in  which  a  few  feet  of  Platteville-Galena  limestone  lies 
above  the  sandstone,  but  these  are  generally  avoided. 

The  methods  of  removing  overburden  vary  according  to  the  amount  of 
material  to  be  removed  and  the  personal  preferences  of  the  operators.    In 


Fig.  19.     Quarry  of  Plant  B,  Ottawa  Silica  Company.     Note  stripped  area  at  right 
of  picture  and  quarry  of  Plant  A  in  left  background. 

general  the  bulk  of  the  overburden  is  loaded  by  steam  shovels  into  auto  trucks, 
wagons  or  dump  cars  which  remove  it  to  some  convenient  place  of  disposal 
(fig.  20).  The  overburden  at  some  quarries  is  dumped  into  a  worked-out 
portion  of  the  quarry  or  into  an  adjoining  gully.  In  others  having  a  very  thin 
overburden,  it  is  scraped  back  from  the  working  face  with  a  drag-line  scraper 
until  sufficiently  large  piles  have  accumulated  to  warrant  larger  scale  opera- 
tions for  their  removal.  After  the  bulk  of  the  overburden  has  been  removed 
the  depressions  in  the  surface  of  the  sandstone  are  commonly  cleaned  out  by 
teams  and  scrapers  and  finally  by  men  with  shovels.  The  top  of  the  sandstone 
is  then  thoroughly  swept  with  stiff  brushes  and  a  final  cleaning  of  any  pockets 
or  holes  effected  with  compressed  air  or  steam.    Thus  the  impurities  from  the 


66 


THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 


overburden  which  might  enter  the  sand  when  it  is  quarried  are  reduced  to  a 
minimum. 

BLASTING 

In  order  to  quarry  the  sandstone  most  efficiently  by  hydraulic  methods,  it 
is  necessary  to  loosen  it  by  blasting.  Several  schemes  are  employed,  one  of 
which  is  to  drill  vertical  holes  5  to  10  feet  deep,  8  or  10  feet  from  the  quarry 
face  and  spaced  6  to  8  feet  apart,  which  are  loaded  with  dynamite.  The 
explosion  of  the  dynamite  loosens  the  sand.  Another  method  consists  of 
drilling  holes  horizontally  into  the  face  at  its  base.     These  holes  are  sprung- 


Fig.  20.  Gasoline  tractor  shovel  and  side  dump  cars  used  for  removing  overburden 
at  the  quarry  of  the  Wedron  Silica  Company.  In  the  background  is  a  cliff  of 
St.  Peter  sandstone  capped  by  glacial  drift.  (Photograph  by  courtesy  of  Wedron 
Silica   Company.) 


with  a  light  shot,  cleaned  out  and  reloaded  with  a  much  larger  charge,  which 
effectively  loosens  the  sand  above  when  exploded.  The  term  "gopher-holing" 
is  applied  to  this  mode  of  blasting.  Water-jet  tripod  or  hand  drills  are  com- 
monly used  for  drilling  the  blast  holes.  Most  of  the  primary  blasting  is  done 
in  the  fall  and  the  sand  allowed  to  weather  and  disintegrate  during  the  winter, 
so  that  by  spring  a  large  part  of  the  material  has  broken  up  into  loose  grains 
or  slightly  coherent  masses.  Sometimes  after  the  upper  loose  sand  has  been 
quarried,  a  projecting  toe  or  ledge  of  undisintegrated  rock  is  uncovered  at  the 
base  of  the  quarry  face.    A  hole  is  commonly  drilled  horizontally  into  the  base 


QUARRYING 


67 


of  this  toe  by  means  of  a  water- jet  drill  usually  hand  operated,  and  the  toe 
broken  up  with  a  charge  of  dynamite.  This  same  method  is  also  employed  to 
loosen  and  fragment  slides  or  falls  of  large  chunks  of  sandstone.  Dobying  or 
mud  capping  is  commonly  employed  for  breaking  up  large  blocks  of  sandstone 


which  have  survived  the  other  blasting. 


HYDRAULIC  QUARRYING 


With  the  exception  of  the  National  Silica  Company  at  Oregon,  all  the 
companies  producing  washed  sand  employ  hydraulic  methods  in  quarrying. 


Fig.  21.  Hydraulic  quarrying  of  the  St.  Peter  sand.  The  sump  and  pump  are  just 
beyond  the  left  foreground  of  the  picture.  (Photograph  by  courtesy  of  Ottawa 
Silica   Company.) 

This  method  consists  of  directing  a  stream  of  water  under  40  to  120  pounds 
pressure  against  the  blasted  and  weathered  sandstone  as  shown  in  figures  21 
and  22.  The  sand  and  water  flow  away  from  the  quarry  face  to  a  shallow 
depression  or  sump  in  the  center  of  which  is  set  a  steam-operated  sand  pump 
(figs.  23  and  22).  The  intake  of  the  pump  has  an  iron  grating  over  it  which 
prevents  lumps  of  sand  larger  than  about  Y\  inch  from  entering  the  pump. 
The  lumps  of  sand  which  accumulate  on  the  grating  are  periodically  removed 
with  a  perforated  shovel. 


68 


THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


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QUARRYING 


69 


The  number  of  places  in  the  quarry  at  which  sand  will  be  quarried  de- 
pends on  the  quantity  of  sand  it  is  desired  to  produce.  As  different  portions 
of  the  face  are  worked  back  they  become  more  or  less  individualized  into 
separate  rooms  or  openings  (fig.  24).  Converging  to  a  common  point  from 
the  face  of  each  opening  are  a  number  of  pipe  lines  so  spaced  at  the  face  as  to 
handle  conveniently  the  sand  to  be  quarried  by  simply  moving  the  pump  from 
one  to  the  other  of  these  pipes.  As  the  face  is  quarried  back  such  additional 
pipe  lines  as  are  necessary  are  added  to  the  fan-shaped  net  work. 


.  -  •* 


Fig.  23.     Sand   pump   and   sumps  in  quarry  of  the   United   States   Silica   Company. 
(Photograph  by  courtesy  of  the  United  States  Silica  Company.) 


At  the  converging  end  of  the  pipe  lines  is  a  sump.  When  more  than  one 
stream  of  water  and  pump  are  in  operation  at  the  face,  the  sand  is  discharged 
into  this  sump  (figs.  24  and  25).  An  auxiliary  pump  draws  the  sand  from 
the  sump  and  forces  it  into  a  single  main  pipe  line  which  conveys  the  sand  to 
the  drag-belt  elevator.  In  some  quarries  the  gathering  sump  and  auxiliary 
pump  are  omitted. 


70 


THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


■  :Wm'B 

... 

it' 

.....  .            ..,■ 

-;'"';.ir-'r          ;:3S  ■.'-....■;./■'                  ■       .,""".             ■■■''■"-■■'      v.:  '-'''■  ■-'"     ■■■■■■- :z'v     ;*»-:--C 
"       -V;,\..    ':";    ■                     •        - ;                   ;■      .._:,.;;■.    -.     :..;    '■  '                       ,      ;.        :. 

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Fig.  24.  Quarry  of  the  Ottawa  Silica  Company.  One  of  the  openings  is  visible 
in  the  center  of  the  picture.  The  picture  also  shows  the  arrangement  of  con- 
verging pipe  lines  from  the  working  face  to  the  gathering  sump  and  auxiliary 
pump  at  the  extreme  left. 


Fig.  25.     Gathering  sump  in  quarry  of  the  Ottawa  Silica   Company. 


PREPARATION    OF   WASHED    SAND 


71 


ELEVATING  THE   SAND   FROM   THE    QUARRY 

The  sand  and  water  from  the  pipe  line  is  discharged  into  a  wooden  box 
which  surrounds  the  lower  end  of  the  drag-belt  elevator  or  conveyor  (fig.  22). 
This  consists  of  a  long  rubber  and  fabric  belt  about  16  or  18  inches  wide,  to 
which  are  nailed  wooden  blocks  or  paddles  about  three  inches  high,  two  inches 
thick,  and  as  wide  as  the  belt.  These  are  commonly  "soled"  with  pieces  of 
hardwood  about  an  inch  thick,  fastened  to  the  upper  edge  of  the  blocks.    By 


Fig.  26. 


Drag-belt   elevator. 
Ottawa   Silic 


(Photograph   by   courtesy   of 
Company.) 


replacing  these  hardwood  soles  it  is  possible  to  "re-sole"  the  conveyor  without 
removing  the  paddles.  In  figure  26  this  belt  and  the  paddles  are  clearly 
shown.  The  portion  of  the  belt  which  is  descending,  that  is  the  part  showing 
the  paddles,  rides  on  large  pulleys.  The  rising  part  of  the  belt  moves  in  a 
flume.  As  the  paddles  come  around  the  lower  terminal  pulley  of  the  belt 
mechanism,  they  dip  into  the  sand  and  water  in  the  box  which  surrounds  the 
lower  end  of  the  belt,  and  drag  with  them  some  of  the  sand  and  water  into  the 
flume.     The  paddles  and  flume  are  proportioned  so  as  to  have  the  minimum 


72  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

practical  working  clearance,  but  some  of  the  sand  and  water  runs  back  down 
the  flume  from  each  paddle.  It  is  caught  by  the  succeeding  paddle  and  carried 
up  so  that  a  practically  continuous  discharge  of  sand  and  water  occurs  at  the 
upper  end  of  the  belt. 

PRELIMINARY   SCREENING 

The  sand  and  water  from  the  elevator  runs  into  a  cylindrical  screen,  com- 
monly known  as  the  "scalping"  screen.  This  screen  has  perforations  of  T/%,  34, 
or  y2  inch  according  to  the  perf erence  of  the  operator.  For  the  finer  openings 
square-holed  wire  screening  is  used.  The  screens  with  the  larger  openings  are 
commonly  perforated  steel.  As  the  cylindrical  screen  revolves,  the  sand  and 
water  passes  through  it  into  the  washers.  The  material  retained  on  the  screen 
discharges  from  the  lower  end  into  a  box  or  trough  from  which  it  is  com- 
monly disposed  of  by  gravity  to  a  waste  heap.  This  material  consists  princi- 
pally of  lumps  of  sand  held  together  by  iron  or  a  siliceous  cement,  or  of  lumps 
of  marcasite. 

WASHING    THE    SAND 

A  number  of  different  types  of  washers  are  employed  in  producing 
washed  sand.  The  most  common  type  is  a  rectangular  concrete  tank  about  12 
feet  long,  8  feet  wide  and  8  feet  deep  with  a  floor  sloping  toward  the  dis- 
charge end.  The  side  of  the  tank  at  the  discharge  end  has  a  vertical  opening 
about  a  foot  wide  cut  through  the  middle  of  the  entire  side,  and  each  side  of 
this  opening  or  gate  has  a  vertical  slot  of  such  size  as  to  accommodate  pieces 
of  2  by  4  inch  lumber.  As  the  sand  enters  the  washer  from  the  scalping 
screen  a  workman  directs  a  strong  stream  of  water  from  a  hose  on  it.  This 
serves  to  loosen  any  clay  present  and  disintegrate  any  small  lumps  of  sand 
which  still  persist.  The  wash  water  containing  the  clay  in  suspension  flows 
out  of  the  gate  at  the  end  of  the  washer.  As  the  sand  accumulates  in  the 
bottom  of  the  washer,  pieces  of  2  by  4  inch  lumber  are  inserted  in  the  slots 
in  the  sides  of  the  discharge  gate  and  added  from  time  to  time  so  as  to  retain 
the  sand  but  permit  the  wash  water  to  flow  away  unhampered.  The  wash 
water  and  clay  are  disposed  of  in  different  ways.  Some  companies  run  the 
water  into  any  natural  drainage  system  possible.  Others  run  the  water  to  a 
settling  basin  where  the  clay  is  allowed  to  settle  out  and  some  of  the  water 
recovered  or  discharged  to  a  convenient  stream.  From  time  to  time  the 
settling  basin  is  cleaned  out  and  the  clay  removed  to  some  convenient  place  of 
disposal. 

When  one  washer  is  full  the  sand  from  the  screen  is  diverted  to  another 
washer  and  a  valve  in  the  bottom  of  the  first  washer  is  opened.  The  sand 
commonly  passes  by  gravity  to  another  washer  where  the  process  of  launder- 
ing is  repeated.     In  general  the  washers  are  operated  in  pairs  so  that  when  one 


PREPARATION    OF    WASHED    SAND 


7  3 


set  is  filling  up  the  other  is  emptying,  thus  insuring  continuous  performance 


and  handling  of  material. 


DRAINING  THE   SAND 

From  the  second  set  of  washers  the  sand  is  pumped  into  the  draining  bins 
(fig.  27).  As  it  enters  the  bins  it  is  further  washed  by  a  stream  or  spray  of 
water  directed  upon  it.  Two  general  types  of  draining  bins  are  employed, 
those  with  flat  bottoms  and  those  with  inclined  bottoms.  The  former  consist 
of  a  square  or  rectangular  concrete.bin,  with  the  bottom  slightly  sloping  to 


Fig.  27.  Draining  bins  of  Ottawa  Silica  Company.  The  sand  is  pumped  from  the 
washers  into  the  bins  and  may  be  seen  spraying  out  from  the  pipe  at  the  right. 
The  overhead  crane  removes  the  sand  from  the  bins  to  the  driers  beneath  the 
ridge  of  sand  along  the  left  wall  of  the  building.  (Photograph  by  courtesy  of 
Ottawa  Silica  Company.) 


permit  the  water  draining  from  the  sand  to  run  off.  The  bins  of  one  com- 
pany are  30  feet  square  and  12  feet  deep.  Over  the  concrete  floor  of  the  bins 
is  placed  a  layer  of  coarse  cinders  or  gravel,  and  this  in  turn  is  overlaid  by  a 
bed  of  fine  gravel  or  cinders.  A  floor  of  2  by  4  lumber  is  laid  over  the  cinders 
or  gravel.  The  water  from  the  sand  trickles  through  the  cracks  in  the  wooden 
floor  and  through  the  cinders  or  gravel  beneath  and  then  runs  out  of  a  drain 
in  the  concrete  floor. 

The  draining  bins  with  inclined  bottoms  are  rectangular,  square  or  round 
and  are  most  commonly  made  of  wood.    The  floor  of  the  bin  is  inclined  at  an 


74  THE    ST.    PETER    SANDSTONE   OF    ILLINOIS 

angle  of  about  45°  and  the  water  drains  from  the  sand  to  a  trough  which  con- 
veys it  away.  The  sand  is  usually  allowed  to  drain  for  24  hours  or  more 
according  to  the  season  and  character  of  the  weather. 

Where  flat-bottomed  bins  are  used,  the  drained  sand  is  commonly  con- 
veyed to  the  driers  by  overhead  cranes  (fig.  27).  The  inclined-bottom  bins 
are  usually  arranged  so  that  the  sand  discharges  through  doors  in  the  side  of 
the  bin  at  its  deepest  part  directly  on  to  the  driers  (fig.  22). 

DRYING  THE  SAND 

Two  general  types  of  driers  are  in  use,  the  steam  coil  drier  and  the  cylin- 
drical rotary  drier.  The  former  commonly  consists  of  tiers  of  iron  pipe  which 
run  back  and  forth  across  the  length  or  width  of  the  drier.  The  pipes  are 
heated  by  steam.  The  drained  sand  is  placed  upon  these  pipes  and  as  it  dries 
it  falls  between  them  on  to  a  conveyor  belt  which  runs  beneath  the  drier  par- 
allel to  its  longest  dimension.     One  company  has  a  drier  85  feet  long. 

The  cylindrical  drier  consists  of  a  rotating  steel  cylinder,  slightly  inclined 
towards  its  discharge  end.  One  type  of  cylindrical  drier  has  steam  heated 
pipes  on  the  inside,  another  has  a  flame  directed  into  it.  The  wet  sand  is  fed 
into  the  receiving  end  of  the  drier  and  is  dried  during  its  movement  to  the 
discharge  end. 

SCREENING  THE  SAND 

The  sand  from  the  conveyor  belt  which  passes  beneath  the  drier  is  dis- 
charged into  a  bin  from  which  it  is  commonly  conveyed  to  the  top  of  the 
screen  house  by  a  bucket  belt  elevator.  The  elevator  discharges  into  a  bin 
which  distributes  the  sand  to  various  screens.  These  are  commonly  of  the 
vibrating  type.  Many  are  Hummer  or  Whip-tap  screens  and  others  of  home 
manufacture.  Commonly  the  screens  are  employed  in  batteries  of  two  or 
three,  the  screens  of  each  battery  performing  a  similar  part  in  the  operation 
of  screening.  The  various  products  from  the  screens  pass  by  gravity  down 
wooden  spouts  into  the  storage  bins. 

SHIPPING   THE   SAND 

The  box  cars  in  which  the  sand  is  to  be  shipped  are  run  alongside  of  the 
storage  bins  and  the  sand  is  spouted  into  them.  The  cars  are  commonly  lined 
with  paper  before  loading.  Some  glass  companies  have  special  types  of  box 
cars  which  they  own  and  which  are  used  exclusively  for  the  transportation  of 
glass  sand. 

THE    MANUFACTURE   OF    SPECIAL    SANDS    OR   SAND   PRODUCTS 
WASHED   AND  DRAINED   SAND 

Washed  and  drained  sand  is,  as  the  name  implies,  sand  which  has  been 
washed  and  drained  bul   not  dried.    Tt  is  commonly  run  directly  from  the 


PREPARATION    OF   SPECIAL    SANDS 


7  5 


washers  into  hopper-bottom  gondolas  and  allowed  to  drain  on  the  track  before 
shipment. 

STANDARD    OTTAWA    SAND 

This  is  a  very  carefully  screened  sand  all  of  which  passes  a  20-mesh 
sieve  and  is  retained  on  a  30-mesh.  A  special  installation  of  shaker  screens  is 
used  for  sieving  the  sand.  It  is  run  over  a  magnetic  separator  which  removes 
any  pieces  of  steel  that  may  have  got  into  the  sand  from  the  steel  brushes  used 
in  brushing  the  sieves  and  then  is  sacked  for  shipment. 


Fig.  28.  Tube  mills  in  plant  of  National  Silica  Company.  Each  mill  is  jacketed  to 
catch  the  very  fine  silica  dust  produced  during  grinding.  (Photograph  by  courtesy 
of  National  Silica  Company.) 


GROUND    SAND    OR    SILICA 

Ground  silica  is  prepared  by  pulverizing  washed  and  dried  sand  in  tube 
mills  (fig.  28).  They  vary  in  size.  One  plant  has  installed  two  mills,  each  6 
feet  in  diameter  and  22  feet  long.  The  tube  mills  are  lined  with  Belgian  flint 
blocks  and  Danish  flint  pebbles  are  used  as  grinders.  The  tube  mills  are 
slightly  inclined  and  as  they  revolve  the  sand  moves  from  the  receiving  end  to 


76  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

the  discharge  end.  From  the  tube  mills  the  sand  is  elevated  to  bins  which 
feed  the  sacking  machines  used  for  bagging  the  silica  for  shipment.  Inasmuch 
as  silica  dust  is  injurious  to  the  lungs,  dust  collectors  are  commonly  installed 
about  the  dusty  parts  of  the  grinding  operation  or  the  workmen  wear  masks 
to  prevent  inhaling  the  silica  dust.  The  finished  product  commonly  will  pass 
a  170-mesh  sieve  and  be  retained  on  a  200-mesh. 

PRODUCERS  OF  WASHED  SAND 

The  general  procedure  of  quarrying,  washing  and  manufacturing  St. 
Peter  sand  has  been  described.  The  purpose  here  is  to  summarize  the  equip- 
ment at  each  plant  and  point  out  the  salient  departures  in  the  production  of 
sand  which  may  be  peculiar  to  any  of  the  plants  described,  together  with  any 
miscellaneous  items  of  interest  concerning  the  various  quarries  or  plants.  The 
locations  of  the  plants  in  the  principal  producing  area,  the  Ottawa-Utica  dis- 
trict, are  shown  in  figure  29. 

The  plants  will  be  described  in  the  following  order : 

Ballou  White   Sand   Company 
Higby-Reynolds   Silica   Company 
Ottawa  Silica  Company 
Standard   Silica   Company 
United   States   Silica   Company 
Wedron   Silica   Company 
National    Silica    Company 

Ballou  White  Sand  Company 

Location:  west  side  of  Fox  River,  in  SE.  cor.  SW.  J/±  NE.  ^4  sec.  19, 
T.  36  N.,  R.  6  E.,  near  Millington,  Kendall  County. 

Quarry:  pit  quarry;  50-foot  face. 

Overburden :  glacial  gravel  and  boulders,  overlain  by  2  to  3  feet  of  black 
loam.    Average  thickness  about  4  feet. 

Equipment:  cylindrical  scalping  screen,  2  washers,  seven  10  by  20  foot 
inclined-bottom  draining  bins,  2  steam-coil  driers ;  dried  sand  goes  first  over 
cylindrical  Tyler  screen  about  14  mesh,  then  over  stationary  inclined  screen. 
Steam  power.  Sand  conveyed  across  Fox  River  to  railroad  by  bucket  cable 
tram. 

Railroad :  Chicago,  Burlington  and  Quincy. 

Water  for  quarrying  and  washing :  quarry  water.  Wash  water  disposed 
of  into  Fox  River. 

Capacity :  200  tons  per  10  hours. 

Samples:  No.  47  from  the  37-foot  northeast  face;  No.  50,  plant  run; 
Nos.  48  and  49  are  from  one  of  the  lower  beds  in  the  quarry.  The  last  two 
samples  were  taken  about  300  feet  from  each  other. 


PRODUCERS    OF   WASHED    SAND 


77 


78  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

Higby-Reynolds  Silica  Company 

(REYNOLDS    EAST    QUARRY) 

Location :  NW.  cor.  SW.  %  SW.  ji  sec.  10,  T.  33  N.,  R.  2  R,  near 
Utica,  La  Salle  County. 

Quarry:  slope  quarry;  55-foot  face. 

Overburden:  glacial  drift  and  soil,  averaging  about  3  feet  thick. 

Equipment:  flat  scalping  screen,  2  washers,  three  15  by  15  foot  draining 
bins  with  a  16-inch  screw  feed  at  bottom  to  conveyor  belt,  cylindrical  revolv- 
ing oil-fired  drier,  flat  inclined  screen,  52  inches  by  30  feet.    Steam  power. 

Railroad :  Chicago,  Rock  Island  and  Pacific. 

Water  for  quarrying  and  washing:  artesian  well. 

Capacity :  200  tons  per  9  hours. 

Samples :  No.  36  from  quarry  face ;  No.  37  is  plant  run. 

Ottawa  Silica  Company 


Location:  SW.  %  NW.  *4  sec.  10,  T.  33  N.,  R.  3  E.,  northwest  of 
Ottawa,  La  Salle  County. 

Quarry:  pit  quarry;  30-35-foot  face. 

Overburden :  black  loam,  average  thickness  about  one  foot. 

Equipment:  8  by  3  foot  cylindrical  scalping  screen,  4  washers,  four  30 
by  30  by  12  foot  flat-bottomed  draining  bins,  sand  taken  from  draining  bins 
to  drier  by  overhead  clam-shell  crane,  steam-coil  drier,  Hummer  and  Whip- 
tap  screens,  electric  power.   Two  tube  mills,  6  by  22  feet,  for  grinding  silica. 

Railroad:  joint  switch  to  Chicago,  Rock  Island  and  Pacific,  and  Chicago, 
Burlington  and  Quincy,  Illinois  Traction. 

Water  for  quarrying  and  washing:  quarry  water,  well,  and  Illinois  and 
Michigan  Canal.    Wash  water  run  to  settling  tank  and  then  to  canal. 

Capacity:  1400  tons  per  24  hours. 

Samples :  No.  1  from  west  quarry  face ;  No.  2  south  quarry  face ;  No.  3 
east  quarry  face ;  Nos.  4  and  5  are  from  bed  near  bottom  of  quarry  in  east 
face  and  were  taken  about  400  feet  apart ;  No.  6  is  plant  run. 


Location:  NW.  cor.  SW.  yA  sec.  10,  T.  33  N.,  R.  3  E.,  near  Ottawa, 
La  Salle  County. 

Quarry:  pit  quarry;  30-35-foot  face. 

Overburden :  black  loam,  average  thickness  about  one  foot. 

Equipment:  8  by  3  foot  cylindrical  scalping  screen,  4  washers,  six  30  by 
30  by  12  foot  flat-bottomed  draining  bins,  overhead  clam-shell  crane  takes 
sand  from  draining  bins  to  drier,  steam-coil  drier,  Hummer  and  Whip-tap 
screens,  electrically  operated. 


PRODUCERS    OF    WASHED    SAND  79 

Railroad :  joint  switch  to  Chicago,  Rock  Island  and  Pacific,  Chicago, 
Burlington  and  Quincy,  and  Illinois  Traction. 

Water  for  quarrying  and  washing:  quarry  water,  well,  and  Illinois  and 
Michigan  Canal.    Wash  water  to  settling  basin  and  then  to  canal. 

Capacity:  2000  tons  per  24  hours. 

Samples :  No.  7  from  south  face  center  workings ;  No.  8  is  plant  run. 

Standard  Silica  Company 

PLANT    NO.    1 

Location:  NE.  yA  SE.  ]/A  sec.  15,  T.  33  N.,  R.  3  E.,  southwest  of  Ottawa, 
La  Salle  County. 

Quarry:  pit  quarry;  50-foot  face. 

Overburden :  black  loam,  locally  pebbly  or  clayey,  average  thickness  about 
3  feet. 

Equipment :  the  primary  washers  have  a  taper  at  the  end  through  which 
the  wash  water  passes  out.  This  is  said  to  give  the  water  greater  velocity  and 
to  result  in  a  cleaner  sand.  The  secondary  washers  are  the  common  rec- 
tangular type.  There  are  2  of  each  type  of  washers.  Cylindrical  silo  draining 
bins,  10  by  19  feet  with  inclined  bottom,  steam-coil  drier,  "knocker"  screens, 
electric  and  steam  power. 

Railroad :  Chicago,  Burlington  and  Quincy. 

Water  for  quarrying  and  washing:  quarry  water,  wash  water  run  to 
settling  basin  and  then  to  Illinois  River. 

Capacity:  1200  tons  per  day. 

Samples :  No.  43  from  face,  SW.  corner  of  quarry ;  No.  44  is  plant  run. 

PLANT    NO.    2     (FORMERLY    CRESCENT    SILICA    COMPANY) 

Location:  SW.  %  NE.  yA  sec.  16,  T.  33  N.,R.  3  E.,  southwest  of  Ottawa, 
La  Salle  County. 

Quarry :  pit  quarry ;  75-foot  face. 

Overburden :  black  loam,  average  thickness  about  one  foot. 

Equipment:  cylindrical  scalping  screen  2  by  5  feet,  4  washers,  inclined 
bottom  draining  bins,  2  rotary  steam-coil  driers,  vibrating  screens,  electricallv 
operated. 

Railroad:  joint  switch  to  Chicago,  Rock  Island  and  Pacific  and  Chicago, 
Burlington  and  Quincy. 

Water  for  quarrying  and  washing:  quarry  water. 

Capacity:  1200  tons  per  24  hours. 

Samples:  No.  9  from  quarry  face;  No.  10  is  plant  run. 


80  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

United  States  Silica  Company 

Location:  SW.  YA  sec.  16,  T.  33  N.,  R.  3  E.,  southwest  of  Ottawa, 
La  Salle  County. 

Quarry :  pit  quarry ;  face  about  70  feet. 

Overburden:  black  loam,  average  thickness  about  2  feet. 

Equipment:  cylindrical  scalping  screen,  2  washers,  12  draining  bins  with 
inclined  bottoms,  steam-coil  drier,  Whip-tap  screens,  electrically  operated. 

Railroad :  Joint  switch  to  Chicago,  Rock  Island  and  Pacific  and  Chicago, 
Burlington  and  Quincy. 

Water  for  quarrying  and  washing:  quarry  water,  wash  water  to  settling 
basin  to  Illinois  River. 

Capacity:  1200  tons  per  24  hours. 

Samples:  No.  13  from  north  quarry  face;  No.  12  is  plant  run. 

Wedron  Silica  Company 

Location :  center  sec.  9,  T.  34  N.,  R.  4  E.,  at  Wedron,  La  Salle  County. 

Quarry:  pit  quarry,  face  55  to  75  feet. 

Overburden :  glacial  drift  and  soil,  average  thickness  about  10  feet. 

Equipment :  rotary  scalper,  4  washers,  flat-bottom  draining  bins,  over- 
head clam-shell  crane  from  draining  bins  to  drier,  steam-coil  driers,  vibrating 
screens,  electrically  operated. 

Railroad :  Chicago,  Burlington  and  Quincy. 

Water  for  quarrying  and  washing :  quarry  water,  wash  water  to  settling 
basin  to  Fox  River. 

Capacity:  1000  tons  per  24  hours. 

Samples :  No.  17,  plant  run ;  No.  18  face  sample  from  south  face  of  south 
workings ;  Nos.  19  and  20  bed  samples  from  south  face ;  No.  21  face  sample 
from  upper  portion  of  exposure  at  one  time  quarried  as  molding  sand. 

National  Silica  Company 

Location :  NE.  j4  SW.  %  sec.  8,  T.  23  N.,  R.  10  E.,  west  of  Oregon, 
Ogle  County. 

This  company's  operations  are  unique  in  Illinois,  inasmuch  as  the  sand- 
stone is  not  quarried  hydraulically  and  is  washed  by  a  special  apparatus ;  the 
product  is  used  almost  exclusively  for  one  purpose,  namely  ground  silica.  The 
quarry  and  plant  are  therefore  described  in  detail  (fig.  30). 

The  sandstone  quarried  is  more  firmly  consolidated  here  than  in  the 
Ottawa  district  and  it  is  not  feasible,  therefore,  to  quarry  it  by  hydraulic 
methods.  Instead,  regular  rock  quarrying  methods  are  used  (fig.  31).  The 
quarry  is  a  pit  quarry  and  has  a  face  averaging  about  35  feet  in  height.  The 
overburden  is  glacial  drift  and  varies  from  1  to  10  feet  thick.   The  average  is 


PRODUCERS    OF    WASHED    SAND 


about  3  feet.  The  holes  for  the  primary  blasting  are  drilled  with  churn 
drills,  the  secondary  blast  holes  with  jack  hammers.  After  the  sand  has  been 
shot  down  it  is  loaded  with  a  railroad  type  steam  shovel,  1  y2  yard  bucket,  into 
5-yard  side  dump  cars.   Dinkeys  haul  the  cars  to  the  plant.   The  cars  dump  on 


Fig.  30.  Plant  of  National  Silica  Company,  Oregon,  Illinois.  On  the  left  is  the 
building  housing  the  screening  and  pulverizing  machinery,  and  just  behind  the 
tree  in  the  center  of  the  picture  is  the  circular  draining  bin.  The  other  buildings 
house  the  power  plant  and  washing  and  drying  equipment.  (Photograph  by 
courtesy  of  National  Silica   Company.) 


Fig.  31.  Quarry  of  National  Silica  Company  showing  steam  shovel  used  for  loading 
sand,  and  cars  which  transport  the  sand  to  plant.  (Photograph  by  courtesy  of 
National  Silica   Company.) 


to  an  inclined  bar  grizzly  with  3-inch  openings.  (See  fig.  32.)  The  undersize 
falls  into  a  hopper  and  the  oversize  goes  into  a  roll  crusher  set  at  about  3 
inches  and  then  to  the  same  hopper  as  the  undersize.  The  hopper  has  a  cater- 
pillar tread  feed  to  a  conveyor  belt  which  is  about  250  feet  in  length  from 
center  to  center.     A  movable  trip  at  the  upper  end  of  the  belt  distributes  the 


82 


THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

Sand  from  quarry 


Undersize 

* 

Oversize 

* 

1 

" 

Hopper 

1  Roll  crusher  J 

< 

■*■ 1 

I  Caterpillar  tread  feed 


Conveyor  belt 


Movable  trip 


Oversize 


Concrete  bins 
1 


—     _  I  Undersize 

r=^  Cylindrical  screens  f— ^ 


Wet  pan  grinder 


Cylindrical  washer 
HZ 


Sump 


[Drag-belt  elevator    | 

Inclined  screen 

|  Cylindrical  washer  j 

I  Sump  ] 


Drag-belt  elevator 
I  ZZ 

Screw  washers 


Conveyor  belt 


Screw  washers 


|  Circular  draining  bin  j 


Clam  shell  crane 


Steam  coil  driers 


Conveyor  and  elevator  belt 


Screens 


Sand  blast  sand 


Bin 


Weighing  trucks 


Tube  mills 


Concrete  bins 


Clam  shell  crane 


',  Dump-bottom  hopper 


Railroad  cars 


Ground  silica 


Fig.  32.      Flow  sheet  of  plant  of  National  Silica 
Company. 


PRODUCERS    OF    WASHED    SAND 


S3 


sand  to  square  concrete  bins.  From  these  bins  the  sand  feeds  by  gravity  into 
a  2  by  7  foot  jacketed  cylindrical  screen.  The  screen  has  ^2 -inch  openings ; 
the  jacket  is  about  10  mesh.  The  sand  passing  the  screen  goes  to  the  washers. 
The  oversize  from  the  screens  goes  to  a  wet  pan  grinder.  The  sides  of  the 
pan  are  steel  grating  with  34-mdi  vertical  slits.  The  sand  passes  out  through 
these  openings  and  is  conveyed  back  to  the  cylindrical  screen.  The  sand  pass- 
ing the  screen  goes  to  two  cylindrical  concrete  washers  (fig.  33).  There  are 
three  of  these  screening  and  grinding  units.    The  washers  are  full  of  water 


Fig.  33.  Circular  washers  in  plant  of  National  Silica  Company.  Note  the  flume  dis- 
charging into  the  second  washer.  (Photograph  by  courtesy  of  National  Silica 
Company.) 


when  the  sand  from  the  screens  come  in  and  the  addition  of  the  sand  and 
water  from  the  pans  and  screens  causes  the  washer  to  overflow ;  with  the 
overflow  the  clay  is  carried  off.  When  the  first  washer  is  full  of  sand  a  valve 
is  opened  and  the  sand  is  allowed  to  run  out  into  a  sump  from  which  a  drag- 
belt  elevator  conveys  it  to  the  top  of  a  flume  wrhich  discharges  over  an  inclined 
screen  into  the  second  washer  (fig.  33).  About  the  upper  two-thirds  of  the 
screen  is  10  mesh  and  the  lower  third  14  mesh.  From  this  second  washer  the 
sand  again  goes  to  a  sump  and  is  elevated  by  a  drag  belt  to  a  battery  of  5 


84  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

screw  washers.  After  passing  through  these  washers  the  sand  is  conveyed  on 
a  belt  to  a  circular  building  housing  another  set  of  5  screw  washers.  (See 
fig.  30).  These  are  on  an  arm  pivoted  at  the  center  of  the  building.  The  arm 
can  be  moved  so  that  the  washers  discharge  into  any  part  of  the  circular 
draining  bin  which  constitutes  the  lower  portion  of  the  building.  The  sand  is 
removed  from  the  draining  bins  by  a  clam-shell  crane  also  attached  to  a 
movable  arm  pivoted  at  the  center  of  the  building  and  dried  on  steam-coil 
driers.  A  conveyor  belt  and  an  elevator  belt  carry  the  sand  to  the  Hummer 
screens.  During  the  screening  process  all  material  over  16  mesh  is  discarded. 
Some  sand-blast  sand  is  produced  but  a  great  part  of  the  sand  goes  from  the 
screens  to  a  bin  which  feeds  by  gravity  to  weighing  trucks.  The  operators  of 
these  trucks  weigh  out  the  charges  for  tube  mills  of  which  there  are  two 
7  by  22  feet,  six  6  by  11  feet  and  one  6  by  22  feet.  (See  fig.  28).  On  the 
average  about  6  hours  are  required  to  grind  one  charge  of  sand.  The  tube 
mills  are  lined  with  Belgian  flint  bricks  and  French  flint  pebbles  are  used  as 
grinders.  The  plant  is  equipped  throughout  with  dust  collectors.  The 
capacity  of  the  mills  is  about  160  tons  of  ground  silica  per  24  hours.  From 
the  mills  the  ground  silica  passes  into  concrete  bins  from  which  it  is  loaded 
by  an  overhead  clam-shell  crane  into  a  dump-bottom  hopper  which  feeds  by 
gravity  into  railroad  cars.  The  plant  is  operated  by  electricity  throughout. 
Water  for  washing  the  sand  is  secured  from  two  wells  about  180  feet  deep. 
After  use  it  is  run  into  a  settling  pond  and  reclaimed.  The  pond  is  cleaned 
out  periodically  with  a  drag-line  bucket. 

Sample  51  is  from  the  35-foot  face  on  the  east  side  of  the  quarry.  No.  53 
is  plant  run. 

Sample  52  is  from  the  sandstone  exposed  in  the  bluff  along  the  north  side 
of  the  railroad  north  of  the  quarry.  The  beds  have  an  east  dip  of  about  15°. 
The  total  thickness  exposed  and  sampled  is  about  93  feet.  Part  of  the  93  feet 
is  probably  the  same  strata  as  those  from  which  sample  51  was  obtained. 

Crude  Sand 
general  statement 

The  crude  sand  quarries,  or  molding  sand  quarries  as  they  are  sometimes 
called,  are  for  the  most  part  bluff  quarries  in  contrast  to  the  washed  sand 
quarries  which  are  mostly  pit  quarries.  The  crude  sand  workings  are  with 
three  exceptions  in  the  bluff  along  Illinois  River  between  Ottawa  and  Utica. 
(See  fig.  29,  p.  77).  In  general  the  sand  is  yellow  and  contains  more  clay 
than  that  of  the  washed  sand  quarries.  As  a  rule  the  crude  sand  quarries  have 
a  comparatively  thick  overburden  whose  removal  is  an  important  economic 
factor  and  item  in  the  production  of  the  sand. 

In  quarrying  the  sand  it  is  the  common  practice  to  drill  blast  holes  to 
about  the  level  of  the  quarry  floor  along  the  upper  edge  of  the  quarry  face 


PRODUCERS    OF   CRUDE    SAND 


85 


with  churn  or  tripod  drills.  When  shot,  holes  drilled  in  this  fashion  bring 
down  a  large  part  of  the  face  at  one  time.  Another  method,  gopher-holing, 
consists  of  drilling  horizontal  holes  into  the  face  with  water- jet  drills.  These 
are  sprung  with  a  light  shot  and  then  cleaned  out  and  re-loaded  with  a  heavier 
charge  which  when  exploded  also  brings  down  a  large  quantity  of  sand. 

Many  different  methods  are  in  use  for  getting  the  sand  from  the  quarry 
face  to  the  railroad  cars.  They  depend  upon  the  location  of  the  quarry  face 
with  reference  to  transportation,  to  some  extent  on  the  physical  character  and 


Fig.   34. 


Churn   drill    used   for   making  primary   blast   holes.      (Photograph 
by   courtesy   of   American    Silica    Sand    Company.) 


topography  of  the  deposit,  and  upon  the  grades  which  it  is  desired  to  produce. 
A  brief  mention  will  therefore  be  made  of  the  method  of  quarrying  under  the 
description  of  each  of  the  quarries. 


PRODUCERS   OF   CRUDE   SILICA   SAND 


The  following  is  a  list  of  the  producers  of  crude  silica  sand  in  Illinois. 
The  operations  of  the  different  companies  will  be  described  in  order. 


American   Silica   Sand    Company 
Bellrose  Sand   Company 
Benson-Richards   Sand   Company 
Buffalo  Rock  Silica   Company 
Commonwealth  Silica  Company 
Federal   Silica   Mines 


$6 


THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 


Higby-Reynolds  Silica  Company 
Illinois  Valley  Silica  Company 
National  Plate   Glass   Company 
Ottawa  Silica  Molding  Sand  Company 
Rock  Island  Silica  Sand  Company 
South  Ottawa  Silica  Sand  Company 
Standard    Silica   Company 
Utica  Fire  Sand  Company 
Wilkinson   Sand   Company 


Fig.  35.     Drag-line  scraper  bringing  sand   on  to  bar  grizzly.      (Photograph 
by  courtesy  of   American   Silica    Sand    Company.) 


American  Silica  Sand  Company 

Center  S.  >4  SE.  %  SW.  %  sec.  10,  T.  33  N.,  R.  2  E.,  near  Utica. 

This  quarry  is  located  in  the  north  bluff  of  Illinois  River.  The  over- 
burden consists  of  about  equal  amounts  of  glacial  drift  and  soil,  and  is 
removed  by  means  of  teams  and  scrapers.  A  face  60  feet  high  is  being  worked 
in  two  benches.    The  holes  for  the  primary  blasting  are  drilled  30  feet  deep 


PRODUCERS   OF   CRUDE    SAND 


S7 


with  a  churn  drill  (fig.  34).  The  disintegrated  sandstone  is  conveyed  by  a 
closed-bottom,  drag-line  scraper  to  a  grate  with  two-inch  openings  (fig".  35) 
and  falls  directly  into  railroad  cars  beneath  the  grate.  Steam  power  is  used. 
The  capacity  of  the  equipment  is  600  tons  per  8  hours. 

The  upper  30  feet  of  sandstone  is  sold  for  molding  sand.  Sample  40 
comes  from  this  upper  30  feet  of  sandstone  from  the  east  face.  Sample  41 
comes  from  the  lower  30  feet  on  the  southeast  side  of  the  quarry.  The  sand 
from  the  lower  30  feet  is  sold  as  fire  and  furnace  sand. 

No.  2  quarry  of  this  company  about  a  half  mile  east  of  Utica  in  the 
north  bluff  of  Illinois  River  was  not  in  operation  (fig.  36). 


Fig.  36.     The  No.  2  quarry  of  the  American  Silica  Sand  Company.     (Photo- 
graph by  courtesy  of  American  Silica  Sand   Company.) 


Bellrose  Sand  Company 

SW.  cor.  NE.  yi  SE.  %  sec.  13,  T.  33  N.,  R.  2  E.,  between  Ottawa 
and  Utica. 

The  quarry  is  located  in  the  north  bluff  of  Illinois  River.  The  over- 
burden averages  about  10  feet  in  thickness  and  consists  of  clay,  coal,  glacial 
drift  and  soil.  It  is  removed  by  a  drag-line  scraper  operating  from  a  dead 
man  and  is  overcast  back  from  the  working  face.  During  the  winter  months 
when  most  of  the  stripping  is  done,  a  steam  shovel  is  also  employed  for  the 
same  purpose.  A  face  of  about  60  feet  is  being  worked.  The  blasted  sand 
is  loaded  with  a  steam  shovel,  one-yard  bucket,  into  a  movable  hopper  set  on 


THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


a  track  above  the  primary  conveyor  belt.  The  hopper  and  conveyor  are 
movable  laterally  along  the  working  face.  The  primary  conveyor  belt  elevates 
the  sand  to  the  screening  and  crushing  plant,  and  discharges  to  a  grizzly.  The 
sand  passing  the  grizzly  goes  through  two  roll  crushers  set  at  5  and  3  inches 
and  then  to  a  cylindrical  screen  with  £4 -inch  perforations.  The  fines  fall 
directly  on  to  a  conveyor  belt  which  discharges  to  the  railroad  cars.  The  over- 
size goes  to  another  roll  crusher  set  at  one  inch  which  discharges  into  a  second 
screen  with  y2-mch.  perforations.  The  fines  from  this  screen  discharge  on  to 
the  conveyor  which  loads  to  the  railroad  cars  and  the  oversize  goes  to  another 
set  of  rolls  set  at  *4  mcn>  and  thence  to  the  loading  conveyor. 

The  capacity  is  about  1200  tons  per  8  hours. 

Sample  25  was  obtained  rom  the  west  end  of  the  quarry  face.  It  does 
not  include  the  upper  8  feet  of  sand  which  was  inaccessible. 


Fig.  37.  The  overburden  at  the  quarry  of  the  Benson-Richards  Sand  Company. 
The  floor  of  the  exposure  is  the  top  of  the  St.  Peter  sandstone.  This  is  over- 
lain by  about  6  feet  of  clay  containing  many  St.  Peter  sand  grains.  Above 
the  clay  and  beginning  at  about  the  level  of  the  man's  waist  is  a  bed  of  coal 
about  18  inches  thick.     The  material  above  the  coal  is  glacial  clay. 


Benson-Richards  Sand  Company 

Center  S.  y2  SE.  Jj  SW.  Yk  sec.  18.  T.  33  N.,  R.  3  E.,  near  Ottawa. 

This  quarry  is  located  in  the  north  side  of  Buffalo  Rock,  an  isolated  rock 
hill  in  the  flood-plain  of  Illinois  River.  The  overburden  has  been  overcast  a 
number  of  times  so  that  the  thickness  of  the  normal  overburden  is  only 
roughly  determinable.  The  following  succession  of  strata  was  uncovered 
during  recent  stripping:     (See  fig.  37.)  Thickness 

Feet 

5.     Glacial    drift   '. ? 

4.     Shale,    gray,    nodular,    plastic    3   to  8 

3.      Coal,    badly    weathered,    friable,    no    pyrite 1   to  2 

2.     Clay,  gray,  with  numerous  St.  Peter  sand  grains 3  to  6 

1.     Sandstone    (St.  Peter) 


PRODUCERS    OF   CRUDE    SAND  89 

The  removal  of  the  overburden  is  accomplished  chiefly  by  a  drag-line 
scraper  operating  from  a  dead  man.  The  coal  uncovered  during  the  opera- 
tions is  saved  for  steam  purposes. 

A  face  of  50  feet  of  sand  is  being  worked.  The  holes  for  blasting  are 
drilled  with  air  drills  and  average  about  13  feet  in  depth.  The  sand  is  con- 
veyed by  a  V-shaped  scraper  to  a  grizzly  with  five-inch  openings.  The  over- 
size consists  principally  of  spalls  which  are  discarded.  The  sand  passing 
the  grizzly  falls  to  a  gasoline-driven  portable  belt  loader  which  discharges 
over  a  ^-inch  screen  into  the  railroad  cars.  The  capacity  is  about  300  tons 
per  8  hours  at  one  loading  point. 

Sample  14  was  taken  from  the  face  at  the  west  end  of  the  quarry,  sample 

15  from  the  bottom  5  feet  of  sand  in  the  west  end  of  the  quarry,  and  sample 

16  from  the  same  bed  at  the  east  end. 

Buffalo  Rock  Silica  Company 

NW.  yA  NW.  yA  sec.  19,  T.  33  N.,  R.  3  E.,  in  Buffalo  Rock. 

The  quarry  is  located  in  the  southwest  corner  of  the  west  end  of  Buffalo 
Rock.  A  face  70  feet  high  is  being  worked.  Roughly  the  upper  30  feet  of 
sand  is  colored  deep  yellow  by  iron  oxide,  but  below  this  depth  the  amount 
of  iron  oxide  decreases  progressively.  The  thickness  of  the  overburden  varies 
from  almost  nothing  to  15  feet,  and  averages  about  9  feet.  A  section  of  the 
overburden  at  the  east  end  of  the  quarry  is  as  follows : 

Thickness 
Ft.  In. 

Soil    7 

Clay    3 

Coal    18  to  30 

Clay    2 

St.   Peter    sandstone 

Stripping  is  carried  on  by  a  Marion  type  7  steam  shovel. 

The  sand  is  loaded  by  a  clam-shell  crane  with  a  50-foot  boom  and  a  1^4- 
yard  bucket  to  a  hopper  at  the  top  of  the  crushing  and  loading  unit  (fig.  38). 
This  unit  is  unique  in  that  it  is  on  the  same  rails  as  the  crane  and  is  moved 
back  and  forth  parallel  to  the  quarry  face  by  the  crane.  The  mobility  of  this 
loading  unit  makes  the  shifting  of  railroad  cars  unnecessary  during  loading 
operations.  From  the  hopper  the  sand  passes  through  a  primary  crusher  on 
to  a  ^4-inch  vibrating  screen.  The  fines  from  this  screen  fall  on  the  conveyor 
belt  which  discharges  to  the  railroad  cars.  The  oversize  from  the  screen  goes 
to  a  set  of  rolls  and  then  to  the  discharge  belt.  The  capacity  of  the  plant  is 
about  60  cars  in  12  hours.  The  sand  is  shipped  on  the  Illinois  Traction 
System. 

Sample  45b  was  taken  from  the  face  of  this  quarry. 


90 


THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 


Commonwealth  Silica  Company 

Center  E.  line  sec.  18,  T.  33  N.,  R.  3  E.,  near  Ottawa. 

The  quarry  is  located  in  the  north  bluff  of  Illinois  River.  The  face  is 
about  50  feet  high  with  an  overburden  of  Pennsylvanian  sediments,  glacial 
drift  and  loess  which  varies  from  a  thickness  which  is  almost  negligible  to  one 
of  25  feet.  A  large  portion  of  the  sandstone  is  colored  deep  yellow  by  iron 
oxide,  and  is  worked  selectively  by  pick,  shovel  and  wheel  barrow.  Continu- 
ous operation  is  not  maintained  and  sand  is  loaded  only  to  fill  special  orders. 
Near  this  quarry  are  entries  of  abandoned  mines  which  were  the  source  of 
St.  Peter  in  the  past. 

Sample  45a  was  taken  from  the  face  of  the  quarry. 


Fig.  38.     The  quarry,  and  loading,  crushing,  and  screening  machinery  of  the  BuffaL 
Rock  Silica  Company.      (Photograph,  courtesy  of  Pit  and  Quarry.) 


Federal  Silica  Mines 

Center  S.  y2  NE.  y4  NE.  y4  sec.  15,  T.  33  N.,  R.  2  E.,  near  Utica. 

The  quarry  is  located  in  the  north  bluff  of  Illinois  River  about  two  miles 
east  of  Utica.  The  overburden  averages  about  18  feet  in  thickness  of  which 
the  lower  16  feet  is  glacial  drift  and  the  upper  2  feet  soil.  The  overburden 
is  removed  by  a  steam  shovel,  24 -yard  bucket,  loaded  into  two-yard  side 
dump  cars,  hauled  by  a  gasoline  dinkey  and  disposed  of  into  an  adjoining 
ravine. 

A  face  of  about  60  feet  is  being  worked  in  benches  of  30  feet.  Blasting 
is  carried  on  by  drilling  horizontal  holes  to  a  depth  of  20  feet.  The  sand  is 
conveyed  from  the  face  by  a  closed-bottom  drag-line  scraper,  steam  operated. 


PRODUCERS   OF   CRUDE    SAND 


91 


to  a  grizzly  with  two-inch  openings,  through  which  it  falls  into  railroad  cars. 
The  capacity  is  about  450  tons  per  8-hour  day. 

Sample  34  comes  from  the  upper  30  feet  of  sand  which  is  sold  as  steel 
molding  sand,  and  sample  35  from  the  lower  30  feet  of  sand  which  is  sold  as 
furnace  bottom  and  fire  sand. 

Higby-Reynolds  Silica  Company 
(higby  canyon  quarry) 

NE.  cor.  SE.  %  NW.  %  sec.  14,  T.  33  N.,  R.  2  E.,  near  Utica. 

This  quarry  is  located  on  the  west  side  of  Higby-Ravine  a  short  distance 
up  the  ravine  from  the  bluffs  of  Illinois  River.  The  overburden  averages 
about  6  feet  in  thickness.     Locally  it  is  glacial  drift  and  soil ;  in  other  places 


Fig.    39.     End    dump    car    discharging    into    railroad    car.      (Photograph    by 
courtesy  of  American  Silica  Sand  Company.) 


it  is  clay,  coal  and  shale.  It  is  removed  by  loading  with  a  steam  shovel,  1 24- 
yard  bucket,  to  4-yard  side  dump  cars  which  are  pulled  by  a  dinkey  to  an 
adjoining  ravine,  and  dumped.  Any  coal  included  in  the  overburden  is  recov- 
ered during  the  stripping  operations. 

Two  levels  of  25  feet  each  are  being  worked.  On  the  upper  level  a  steam 
shovel  with  a  %-yard  bucket  loads  the  sand  into  4-ton  side  dump  cars  which 
are  pulled  by  a  dinkey  to  a  chute  into  which  the  cars  are  dumped.  The  chute 
discharges  into  railroad  cars.  On  the  lower  level  a  V-shaped  or  "arrow"  open- 
bottom  scraper  and  drag  line  convey  the  sand  to  a  grizzly  through  which  the 
sand  discharges  into  11-ton  end  dump  cars.  These  are  pulled  by  cable  and 
dumped  by  a  trip  into  railroad  cars  (fig.  39).  The  output  capacity  from  both 
levels  is  about  1800  tons  per  8  hours. 


92  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

The  sand  from  the  upper  level  is  sold  as  steel  molding  sand.  Sample  28 
comes  from  the  north  face  of  the  upper  level ;  sample  29  comes  from  the  east 
face  of  the  upper  level ;  sample  32  is  from  the  lower  level.  Most  of  the  sand 
produced  from  the  lower  level  is  sold  for  core  sand.  Certain  portions  of  the 
lower  sand  are  sold  as  welding  sand  and  magnesia  sand.  Sample  30  comes 
from  a  5-foot  bed  of  welding  sand  and  sample  31  from  an  8-foot  bed  of 
magnesia  sand. 

Higby-Reynolds  Silica  Company 

(REYNOLDS   WEST   QUARRY) 

NE.  yA  SE.  y  SE.  y  sec.  9,  T.  33  N.,  R.  2  E.,  near  Utica. 

This  quarry  is  located  in  the  north  bluff  of  Illinois  River  and  is  west  of 
the  washed  sand  quarry  owned  and  operated  by  the  same  company.  The  over- 
burden averages  about  2  feet  in  thickness  and  consists  of  glacial  drift  and  soil. 
It  is  removed  by  teams  and  scrapers  to  a  dump  heap. 

A  face  about  100  feet  high  is  being  worked  in  two  benches  of  65  and  35 
feet.  The  upper,  or  65-foot  face,  is  worked  by  drilling  65-foot  holes  with  a 
churn  drill  and  the  entire  face  is  shot  down  at  once.  The  lower  face  was  not 
being  worked  when  the  quarry  was  visited.  Drilling  of  secondary  blast  holes 
in  large  sandstone  blocks  is  done  with  a  steam  jackhammer.  Two  distinct 
quarrying  units  are  in  operation,  each  consisting  of  a  closed-bottom  drag-line 
scraper  operated  by  a  steam  engine,  which  conveys  the  sand  from  the  face  to 
a  grizzly  with  3-inch  openings.  The  sand  falls  through  the  grizzly  to  11 -ton 
end  dump  cars  which  are  pulled  by  a  dinkey  to  the  railroad  spur  where  they 
dump  into  the  railroad  cars.     The  capacity  is  about  1100  tons  per  9  hours. 

Sample  38  is  from  the  east  face  of  the  upper  or  65-foot  ledge.  Sample  39 
is  from  the  lower  35  feet  of  sandstone.  When  the  market  warrants,  the  lower 
face  is  worked  for  furnace  bottom  sand. 

Illinois  Valley  Silica  Company 

NW.  y4  SW.  y4  sec.  18,  T.  33  N.,  R.  3  E.,  near  Ottawa. 

The  quarry  is  located  in  the  north  bluff  of  Illinois  River.  The  over- 
burden averages  about  10  feet  in  thickness  and  where  thick  is  made  up  as 
follows : 

Thickness 
Ft.         In. 

5.     Glacial  drift  and   soil -     1  to  3 

4.     Shale    14± 

3.     Coal _ 1  10 

2.     Fire   clay,   sandy 1  to  3 

1.     St.  Peter  sandstone 

The  overburden  is  removed  by  a  full  revolving  drag  line  with  a  long 
boom  and  a  drag-line  bucket.  It  is  loaded  into  dump  cars  and  disposed  of  in 
a  nearby  ravine. 


PRODUCERS   OF   CRUDE   SAND  93 

The  height  of  the  quarry  face  varies  from  50  to  65  feet  and  averages 
about  60  feet.  Blast  holes  are  drilled  with  a  well  drill  to  a  depth  of  60  to  65 
feet  and  the  entire  face  shot  at  one  operation.  The  blast  holes  are  spaced  15 
feet  apart  and  15  feet  from  the  face.  A  V-shaped  open-bottom  drag-line 
scraper  conveys  the  sand  to  a  rail  grizzly  with  6-inch  openings.  The  sand  is 
reduced  by  sledging  until  it  passes  the  grizzly.  It  falls  through  the  grizzly 
to  a  conveyor  belt  which  takes  it  to  a  cylindrical  screen  with  y2 -inch  square 
mesh.  The  fines  from  this  screen  fall  to  a  conveyor  belt  which  carries  them 
to  the  railroad  cars.  The  oversize  goes  to  a  jaw  crusher  set  at  2  inches  and 
then  to  a  set  of  rolls  set  for  )4  inch.  The  sand  coming  from  the  rolls  falls 
on  to  the  same  conveyor  which  takes  the  fines  from  the  cylindrical  screen  to 
the  railroad  cars.    The  capacity  is  about  1000  tons  per  9  hours. 

Sample  26  is  a  grab  sample  taken  from  ten  loaded  railroad  cars.  The 
character  of  the  quarry  face  made  other  sampling  impossible. 

National  Plate  Glass  Company 

SW.  %  NW.  yA  sec.  15,  T.  33  N.,  R.  3  E.,  near  Ottawa. 

This  quarry  is  about  1200  feet  long  and  65  feet  wide  and  is  located  on 
the  northwest  side  of  and  close  to  Illinois  River.  The  overburden  is  3  to  8 
feet  thick  and  consists  largely  of  black  and  brown  soil  with  a  little  glacial 
gravel  and  clay  just  above  the  sandstone.  ,It  is  overcast  into  piles,  and  then 
is  loaded  by  a  steam  shovel  and  locomotive  cranes  into  railroad  cars  in  which 
it  is  conveyed  to  waste  piles. 

The  quarry  is  being  deepened  in  12-foot  benches.  The  present  face  of 
the  quarry  is  about  30  feet.  The  blast  holes  are  drilled  8  feet  apart  on  a 
square  pattern.  During  blasting  the  sand  is  so  broken  up  that  it  requires  no 
further  treatment.  It  is  loaded  to  railroad  gondolas  by  a  steam  locomotive 
clam-shell  crane  with  a  65-foot  boom.  The  crane  moves  back  and  forth  on 
tracks  which  parallel  the  length  of  the  quarry. 

The  entire  output  of  the  quarry  is  used  by  the  National  Plate  Glass 
Company  at  their  plant  a  short  distance  away  for  grinding  and  polishing 
glass.  Sample  24  was  taken  from  the  east  end  of  the  present  quarry.  Sample 
23  was  taken  from  the  north  end  of  another  older  quarry  a  few  hundred  feet 
west  of  the  present  quarry  which  is  also  a  source  of  grinding  and  polishing 
sand.  The  old  quarry  has  a  40-foot  face.  It  was  not  in  operation  when 
visited. 

Ottawa  Silica  Molding  Sand  Company 

Center  SE.  VA  sec.  18,  T.  33  N.,  R.  3  E.,  near  Ottawa. 

This  quarry  is  located  in  the  north  face  of  the  isolated  rock  hill  known 
as  Buffalo  Rock.  The  overburden  varies  greatly  in  thickness.  It  has  been 
overcast  a  number  of  times  and  consequently  the  thickness  is  hard  to  deter- 
mine.    During  stripping  operations  the  following  section  was  revealed : 


94  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

Thickness 
Feet 

5.     Soil    and    glacial    drift - 2 

4.     Shale,    plastic,   gray,   nodular.     Upper   beds   which   are    covered   by   soil    and 

drift  probably  contain   sandstone  lentils 18± 

3.     Coal,   woody,   locally  charcoal 2  to  3 

2.     Clay,  gray,   amorphous,  containing  many  St.  Peter  grains 2  to  7 

1.     St.  Peter  sandstone 

A  steam  shovel  and  gasoline  shovel  are  used  to  load  the  overburden  which  is 

dumped  in  an  adjoining  valley. 

The  quarry  has  about  a  60-foot  face.     The  holes  for  blasting  are  drilled 

with  air  drills  to  the  entire  depth  of  the  face.  The  broken  sandstone  is  loaded 

by  a  revolving  electric  shovel  with  a  1  1/3-yard  bucket  (fig.  40)  to  a  grizzly 


M 


J:& 


■; M 


~^ 


Mjt^t  jK 


Fig.  40.     The  quarry  and  plant  of  the  Ottawa  Silica  Molding  Sand  Company. 

with  6-inch  openings  over  a  large  hopper.  The  sand  falls  from  the  hopper  to 
a  conveyor  belt  which  carries  it  to  the  crushing  plant  located  a  short  distance 
away  from  the  quarry.  The  belt  takes  the  sand  to  a  4  by  16-foot  revolving- 
screen  with  y2-moh  perforations.  The  sand  passing  this  screen  goes  by  a 
conveyor  belt  to  the  railroad  cars.  The  oversize  from  the  revolving  screen 
goes  to  a  hammer  mill  and  through  it  to  a  conveyor  belt  which  takes  the  sand 
to  a  vibrating  screen  with  ^-inch  openings.  The  undersize  goes  by  conveyor 
to  cars.  The  oversize  is  removed  by  wheel  barrow  and  discarded.  The  capacity 
of  the  plant  is  about  1500  tons  per  9  hours. 

Sample  11  is  taken  from  the  face  of  sand  exposed  in  this  quarry. 


Rock  Island  Silica  Sand  Company 

NW.  cor.  sec.  16,  T.  33  N.,  R.  3  E.,  near  Ottawa. 

This  quarry  is  located  a  short  distance  northeast  of  Twin  Bluffs  in  the 
north  wall  of  Illinois  Valley.  The  overburden  is  heavy  and  the  operations 
not  extensive. 


PRODUCERS    OF   CRUDE    SAND  95 

The  quarry  was  not  in  operation  when  it  was  visited  but  the  sand  is 
apparently  loaded  by  hand  into  wheelbarrows  in  which  it  is  wheeled  to  the 
railroad  cars. 

Sample  42  is  from  the  25  feet  of  sandstone  exposed  at  this  quarry. 

South  Ottawa  Silica  Sand  Company 

Center  S.  y2  NW.  %  NW.  %  sec.  14,  T.  33  N.,  R.  3  E.,  near  Ottawa. 

This  quarry  is  located  in  the  flat  of  Illinois  River  just  north  of  the  bluff 
on  the  south  side  of  the  stream.  The  overburden  averages  about  2  feet  in 
thickness  and  consists  of  brown  and  black  loam.  It  is  overcast  away  from 
the  quarry  face  into  piles  by  a  full  revolving  steam  crane  with  a  50-foot  boom 
and  2-yard  bucket. 

The  quarry  is  rectangular,  long  and  narrow,  and  has  a  30-foot  face.  It  is 
being  lengthened  to  the  west.  The  blast  holes  are  drilled  horizontally  and  the 
broken  sandstone  loaded  into  a  hopper  by  the  same  steam  crane  used  at  times 
for  moving  overburden.  The  crane  is  situated  on  the  upper  edge  of  the 
quarry  face.  From  the  hopper  the  sand  feeds  into  a  cylindrical  rotary  grizzly 
made  of  steel  rails  set  %  inch  apart.  The  sand  falls  through  the  grizzly  on 
to  a  conveyor  belt  which  deposits  it  in  the  railroad  cars.  The  grizzly  and  belt 
are  operated  by  electricity.   The  capacity  is  about  1200  tons  per  8  hours. 

Sample  45  is  from  the  west  face  of  the  quarry. 

Standard  Silica  Company 
(plant  no.  3) 

Center  NE.  %  SW.  ]/A  sec.  13,  T.  33  N.,  R.  2  E.,  between  Ottawa  and 
Utica. 

This  quarry  is  owned  by  the  same  company  operating  the  washed  sand 

plants  in  the  Ottawa  district.   It  is  located  in  the  north  bluff  of  Illinois  River. 

The   overburden   averages   about  6   feet   in   thickness   and   consists   of   the 

following : 

Thickness 
Ft.         In. 

5.     Soil   and  glacial  drift 1  to  2 

4.     Shale   2  to  3 

3.     Coal 1  10 

2.     CI  ay ,  sandy 1  to  2 

1.     St.  Peter  sandstone 

The  overburden  is  removed  by  steam  shovel  and  dump  auto  trucks. 

A  face  about  55  feet  high  is  being  worked.  It  is  shot  by  gopher  holing. 
Holes  are  drilled  about  20  feet  into  the  base  of  the  face,  sprung  with  a  light 
shot,  cleaned  out  and  reloaded  with  a  heavy  charge.  Two  or  three  holes  are 
usually  shot  at  one  time.  The  sand  is  conveyed  from  the  face  by  a  drag-line 
scraper  to  a  grizzly  with  4-inch  openings,  through  which  it  passes  to  a  revolv- 


96  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

ing  screen.  The  oversize  from  this  screen  is  discarded  and  the  sand  passing 
falls  to  a  pile  from  which  it  is  loaded  by  a  drag-line  scraper  to  12-ton  end 
dump  cars.  These  are  pulled  by  cable  to  a  platform  with  a  trip  and  dis- 
charged to  the  railroad  cars.  Steam  power  is  used  for  the  quarrying  opera- 
tions. The  capacity  of  the  quarry  is  about  1000  tons  per  9  hours. 
Sample  27  was  taken  from  the  face  at  center  of  the  quarry. 

Utica  Fire  Sand  Company 

SW.  cor.  NW.  yA  NW.  VA  sec.  14,  T.  33  N.,  R.  2  E.,  near  Utica. 

This  quarry  consists  of  two  individual  workings  which  are  essentially  the. 
same.  The  overburden  on  the  sandstone  averages  about  8  feet  in  thickness 
and  is  removed  by  teams  and  scrapers.  It  consists  of  about  6  feet  of  glacial 
drift  and  2  feet  of  soil. 

A  face  about  70  feet  in  height  is  being  worked.  The  sand  is  moved  by 
closed-bottom  scrapers  to  a  grizzly  with  5-inch  openings  which  discharge  into 
the  railroad  cars.  The  scraper  is  operated  by  a  steam  engine.  The  capacity 
production  is  about  800  tons  per  9  hours. 

The  sand  is  sold  principally  for  steel  molding.  Certain  beds  of  sand, 
however,  are  quarried  for  magnesia  and  core  sand  when  demand  warrants 
such  a  procedure. 

Sample  33  was  taken  from  the  northwest  face  of  the  westernmost  of  the 
two  workings.  The  upper  8  feet  of  sandstone  was  inaccessible  and  is  not 
represented  in  the  sample. 

Wilkinson  Sand  Company 

NE.  cor.  SW.  yA  NW.  yA  sec.  16,  T.  34  N.,  R.  4  E.,  near  Wedron. 

The  quarry  is  located  at  the  intersection  of  a  small  valley  and  the  west 
bluff  of  Fox  River.  A  30-  to  70-foot  face  is  being  worked.  The  upper  15 
feet  of  sandstone  is  brown  and  streaked  with  yellow  and  the  lower  15  feet 
buff  or  white.  The  overburden  averages  about  4  feet  in  thickness  and  consists 
of  soil  and  a  little  gravel.  The  holes  for  blasting  are  drilled  28  feet  deep 
with  water-jet  drills,  and  the  sand  is  loaded  by  a  24 -yard  steam  shovel  to 
4-yard  side  dump  cars  which  are  pulled  to  a  tressel  by  a  dinkey  and  dumped 
directly  into  railroad  cars.  The  capacity  of  the  operation  is  about  20  cars  per 
12  hours.  The  sand  is  shipped  on  the  Chicago,  Burlington  and  Quincy 
Railroad. 

Sample  45c  is  from  the  face  of  this  quarry. 

Grades  of  Washed  and  Crude  Sand  Produced 
washed  sand 

No  strictly  standardized  grades  of  washed  sand  are  produced.  However, 
the  different  grades  sold  group  themselves  in  a  general  way  as  follows: 


GRADES   OF   SAND    PRODUCED  97 

MINE-RUN    SAND 

Mine-run  sand,  sometimes  called  quarry-  or  plant-run  sand,  is,  as  the 
name  implies,  the  sand  as  it  is  delivered  from  the  drier  without  preparation 
further  than  washing  and  drying.  The  size  of  the  sand  varies  somewhat 
according  to  the  particular  quarry  and  the  portion  of  that  quarry  from  which 
it  comes.  This  type  of  sand  is  used  commercially  when  the  size  of  the  grains 
is  not  important. 

WASHED   AND   DRAINED  SAND 

This  type  of  sand  is  the  same  as  mine-run  except  that  it  is  not  dried.  It 
is  commonly  run  from  the  washers  directly  to  railroad  cars  and  allowed  to 
drain  on  the  track.  It  is  used  chiefly  for  steel  molding  when  a  sand  free  from 
natural  bond  is  desired. 

SAND-BLAST    SAND 

Sand-blast  sand  is  in  general  the  coarsest  of  the  manufactured  grades  of 
sand.  Specifications  of  the  manufacturer  vary  somewhat  but  in  general  from 
95  to  100  per  cent  is  retained  on  a  40-mesh  sieve  and  100  per  cent  or  less 
passes  the  20-mesh  sieve.  As  the  name  suggests  the  sand  is  sold  principally 
for  sand  blasting,  and  also  for  grinding  and  polishing,  filter  and  roofing  sand. 

GLASS    SAND 

This  is  a  very  variable  grade  of  sand.  Following  are  the  data  on  the 
size  of  the  sand  sold  for  glass  given  by  the  various  producers :  65  per  cent 
through  40  mesh,  85  per  cent  retained  on  60  mesh ;  quarry  run ;  through  35 
mesh  and  retained  on  65  mesh ;  80  per  cent  retained  on  60  mesh ;  all  through 
30  mesh ;  70  per  cent  through  40  mesh,  all  retained  on  70  mesh.  This  grade 
of  sand  has  many  uses  outstanding  among  which  are  for  making  plate  glass, 
as  engine  sand,  and  in  the  manufacture  of  carborundum,  stucco,  and  sodium 
silicate. 

BANDING    SAND 

Banding  sand  is  a  relatively  fine  grade  of  sand.  It  commonly  all  passes 
50  mesh  and  is  largely  retained  on  about  120  mesh.  It  is  used  principally  for 
frosting  and  polishing  glass,  for  certain  types  of  sand  blasting  where  a  fine 
sand  is  desired,  for  surfacing  fireproof  roofing  and  in  making  soaps. 

MISCELLANEOUS 

Some  producers  make  grades  known  as  extra  fine,  double  extra  fine,  or 
other  like  names.    These  grades  are  commonly  sand  through  60  or  80  mesh. 

GROUND    SILICA 

Ground  silica  prepared  by  grinding  sand  commonly  varies  between  90 
and  300  mesh  according  to  the  use  for  which  it  is  intended.     Some  companies 


98  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

which  have  dust  collectors  around  their  tube  mills  sell  the  accumulated  silica 
dust  as  air-floated  silica.  It  is  a  fine  grade  of  ground  silica.  Ground  silica  is 
sold  as  a  mold  wash,  and  for  making  glazes,  metal  polishes,  abrasive  soaps, 
composition  flooring,  paint  fillers  and  the  like. 

CRUDE  SAND 

No  accurately  delineated  grades  of  crude  sand  are  produced.  According 
to  the  purposes  to  which  the  user  finds  the  sand  best  suited,  the  quarry 
product  is  sold  as  steel  molding  sand,  core  sand,  fire  sand,  furnace  bottom 
sand,  and  welding  sand.  No  attempt  is  generally  made,  however,  to  produce 
a  sand  of  a  standard  sieve  analysis.  All  the  above  grades  of  sand  are  gen- 
erally sold  without  further  preparation  than  reduction  to  pass  a  grizzly  or 
screen  with  openings  which  may  vary  from  ^-inch  to  3  inches.  Any  further 
crushing  or  screening  of  the  sand  is  done  at  the  foundry  or  plant  where  the 
sand  is  used.  The  variations  in  the  physical  constitution  of  the  crude  sand 
sold  for  molding  and  the  like  are  illustrated  by  the  analyses  given  in  the  table 
of  fineness  tests  (pp.  148,  150). 


:hapter  v— the  uses  of  sand  and   OF  THE  ST.  PETER 

SAND 

This  chapter  is  intended  as  a  compendium  of  the  uses  of  sand  with  par- 
ricular  reference  to  the  St.  Peter  sand.  In  describing  the  uses  of  sand  the 
ilan  followed  includes  a  brief  statement  of  the  use  the  particular  sand  serves, 
"he  specifications,  if  any,  for  the  sand,  and  a  brief  discussion  of  the  properties 
jf  the  St.  Peter  sand  which  makes  it  particularly  suited  to  the  use  mentioned. 
The  uses  of  sand  are  listed  below  in  the  order  of  discussion. 

Page 

Abrasive,  ground  sand   as  an 101 

Absorbent,  sand   as  an 101 

Agricultural  sands 101 

Annealing,  sand  for 101 

Asbestos  shingles,  ground  sand  for 101 

Asphalt   pavements,    sand    for 101 

Asphaltic  flooring,   sand   for 104 

Backing  sand 104 

Ballast  for  ships,  sand  as  a 104 

Banding  sand 104 

Bedding  for  stock  cars 105 

Bird   grit    105 

Brass  sand 105 

Brick,   sand  for   clay 105 

Brick  molding,  sand  for 105 

Brick,   sand   for   silica 106 

Brick,   sand   for   sand-lime 106 

Brick  pavements 107 

Burnishing  sand    108 

Carborundum,  sand  for  the  manufacture   of 109 

Cements,   sand  for 109 

Chemical  purposes,  sand  for .  . 109 

Coking   sand    110 

Concrete,  sand  for 110 

Core   sand Ill 

Cuspidors,  sand  for Ill 

Cutting  and  sawing  sand Ill 

Dental  purposes,  sand  for 112 

Dispelling  fog,  sand  for 1 12 

Enameling,  sand  for 112 

Engine   sand    113 

Erasers,  sand  for 113 

Explosives,   sand   for 113 

Facing  sand  and  silica  mold  wash  for  foundry  use 113 

Facing  tile  and  brick,  sand  for 114 

Ferro-silicon  and   other  silicon   alloys,  sand  for  making ..  115 

Fertilizer  filler,  sand   as  a 115 

Filler,   sand   as   a 115 

Filling  mines,  §and  for 115 

Filter    sand    115 

Fire  sand 116 

Floor  sand    116 

Flux  in  metallurgy,   sand   as   a 116 

99 


100  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 


PAGE 

French   sand    116 

Friction  sand 117 

Fused  silica,  sand  for  making 117 

Furnace   and   fire   sand 117 

Glass  sand 118 

Glazes,  sand  for  making 122 

Golf  tees,  traps,  hazzards,  and  greens,  sand  for 122 

Grinding   and   polishing  sand 123 

Grinding  wheels,   sand   for 123 

Horticultural   sands    123 

Hour-glass  sand    124 

Icy  streets  and  walks,  sand  for  use  on 124 

Loam    124 

Matches,   sand   for 124 

Moisture  pad,  sand  as  a 125 

Mold  wash,  silica  or  sand 125 

Molding  sand    125 

Mortar  sand 130 

Paint  manufacture,  sand  for  use  in 130 

Parting  sand 131 

Placing  sand    131 

Plasters,    sand    for 131 

Plugging  oil  wells,   sand  for , 132 

Polishing  sand    133 

Pottery,  sand  for  use  in  the  manufacture  of 133 

Poultry  and  bird  grit 134 

Railroad    ballast,    sand    as 134 

Railroad    fills,    sand    for 134 

Refractory  mortars  and  cements,  sand  for 135 

Refractory  ware,  sand  for 135 

Roofing  sand    135 

Saggar  or  placing  sand 136 

Sandbags,   sand   for 136 

Sand-blast   sand    136 

Sand  baths,  sand  for 137 

Sand-clay   roads    137 

Sand  finishing  painted   surfaces,   sand   for 138 

Sand  finishing  plaster  walls,  sand  for 138 

Sand  paper    138 

Sand   piles,   sand   for 133 

Sand  seals,  sand  for 138 

Sand  tables  and  sand  piles,  sand  for 139 

Sawing  sand 139 

Scouring  sand   139 

Setting   sand 139 

Sidewalks,    sand    for 139 

Silicon,   sand   for  making 139 

Soaps,  sand  for  use  in 140 

Sodium  silicate    (water  glass),   sand  for  making 140 

Standard   Ottawa  sand 140 

Stone-block   pavements,   sand    for 140 

Stucco,  sand  for 140 

Sweeping   compounds,    sand    in 141 

Tar  and  roofing  paper,  sand  in 141 

Terrazzo   floors,    sand    for 141 

Testing  detonators,  sand  for 141 

Testing  sand  ;  Standard  Ottawa  sand 141 

Tumbling  sand 141 

Water  glass,   sand   for  making 142 

Welding,  sand  for 142 

Wood-block  pavements,  sand   for 142 


USES    OF   SAND  101 

Ground  Sand  as  an  Abrasive 

Ground  sand  is  used  as  an  abrasive  in  metal  polishes,  soaps,  and  scouring 
pastes,  for  polishing  bone  and  pearl  buttons,  and  as  a  cleaning  and  polishing 
agent  in  tooth  pastes  and  by  dentists. 

Sand  as  an  Absorbent 

Before  the  time  of  blotting  paper,  sand  was  sprinkled  over  wet  writing 
to  absorb  surplus  ink.  It  is  used  at  the  present  time  to  a  limited  extent  as  an 
absorbent  for  strong  chemical  liquors.  A  sand  composed  of  fine,  rounded 
grains  is  preferred  for  this  purpose. 

Agricultural  Sands 

Sand  is  sometimes  added  to  heavy  soils  to  improve  their  texture  It  in- 
creases the  openness  of  the  soils  which  results  in  freer  drainage.  Agricultural 
testing  sand  is  used  by  laboratories  for  making  tests  on  soils.  The  sand  used 
for  this  purpose  is  a  well-graded,  high  silica  sand. 

Sand  for  Annealing1 

To  cool  hot  articles  very  slowly,  they  are  sometimes  covered  with  fine 
sand,  called  annealing  sand,  which  prevents  the  rapid  escape  of  heat  In 
general  any  fine  sand  is  satisfactory  for  annealing  purposes. 

Ground  Sand  for  Asbestos  Shingles2 

As  much  as  40  per  cent  of  silica,  ground  to  pass  200  mesh,  is  sometimes 
used  m  the  manufacture  of  asbestos  shingles.  It  is  essential  that  the  silica  be 
colorless. 

Sand  foe  Asphalt  Pavements 

_  Asphalt  cement,  prepared  by  mixing  refined  asphalt  with  a  flux  and  heat- 
ing it,  is  used  for  making  three  different  types  of  pavements,  each  of  which 
may  involve  the  use  of  sand.  The  three  types  of  pavements  are :  sheet  asphalt 
asphaltic  concrete,  and  asphalt  block  pavements.  Then-  construction  and  the 
requirements  for  the  sand  for  each  will  be  discussed  in  order. 

SHEET  ASPHALT  PAVEMENTS 

A  sheet  asphalt  pavement  consists  primarily  of  a  concrete  foundation  a 
binder  course  of  asphalt  cement  and  stone,  and  a  wearing  course  of  asphalt 
cemen^and  sand.    The  saud  used  in  the  concrete  should  presumably  meet  the 

soSy'r  AHBi?.and?  a"d  cru*e<J  rocks,  vol.  2,  p.  228,  London    1923 
P.   stint   H"   Slh0a  '"  Canada'  Pa"  I:  CanaakPDePt.'Minnet  Mines  Branch   No.    555, 


102 


THE    ST.    PETER    SANDSTONE   OF    ILLINOIS 


requirements  specified  for  concrete  on  page  110.  The  binder  course  is  of  two 
kinds,  the  open  and  the  closed.  In  the  former  the  use  of  sand  is  uncommon 
or  merely  incidental ;  in  the  latter,  however,  the  sand  is  added  to  fill  the  voids 
between  the  pieces  of  stone.  One  large  city  uses  sufficient  sand  to  make  up 
about  25  per  cent  of  the  total  batch  of  the  binder.3  No  specifications  are 
reported  for  sand  for  use  in  the  closed  binder  course. 

The  wearing  or  upper  course  of  a  sheet  asphalt  pavement  is  commonly 
composed  of  about  three-fourths  sand  and  one-fourth  asphalt  cement  and 
filler  which  may  be  either  Portland  cement  or  rock  dust.  The  character  of  the 
sand  is  an  important  item  in  this  portion  of  the  pavement. 

The  sand  should  be  hard,  durable,  and  free  from  organic  material  and 
easily  broken  rock  fragments  such  as  shale,  coal  and  slate.  It  should  not  con- 
tain clay  or  loam  except  in  very  small  amounts.  Regarding  the  shape  of  the 
grains  of  the  sand  to  be  used  Agg  says :  "It  is  generally  thought  that  the 
sharp  sand  is  better  than  sand  made  up  of  rounded  particles,  but  this  cannot 


Table   5. — Standard  gradings  for  sand  for  sheet  asphalt  pavements 


Passing 
sieve  No. 

Richardson's  Gradingsa 

Forrest's 

Grade  of 
sand 

Ideal  for  heavy 
traffic 

Per  cent 

Permissible  for 
light  traffic 

Per  cent 

Permissible 
Grading^ 

Per  cent 

Dust                

200 

00.0 

oo.o 

00.0 

Fine         

100 

17.0 

26.0 

30.0 

13.0 

80 

17.0 

50 

Total 34 

30.0 

20  to  30 

40 

13.0 

30 

Total                    43 

43.00 

Not  over 

10  0 

30.0 

o.o 

40 

...  20    . 

8  0 

10 

.    5.0 

8 

Total 23 

0  0 

20  to  30 
Not  over 

Total                   100 

100     

10 
100 

aByrne,  A.  T.,  A  treatise  on  highway  construction,  p.  246,  New  York,  J.  "Wiley  & 
Sons,   1913. 

7>Forrost,  C.  N.,  Chief  Chemist,  Barber  Asphalt  Paving  Co.,  in  private  letter  dated 
August  17,   1917.     From  Baker,  I.  O.,  op.   cit,  p.   425. 

.".Baker,  I.  O.,  A  treatise  on  roads  and  pavements,  p.  418,  New  York,  J.  Wiley  &  Sons, 
1920. 


USES   OF  SAND 


103 


Table,  6. — Average  grading  of  sands  recently  used  in  sheet  asphalt  pavements0' 


Fine  sand 

Medium  sand 

Coarse  sand 

City 

Passing 
sieve  No. 

Total 

Passing 
sieve  No. 

Total 

Passing 
sieve  No. 

Total 

o 

T3  O 
C     . 

100 

80 

50 

40 

30 

20 

10 

pa 

Per 
cent 

Per 

cent 

Per 

cent 

Per 
cent 

Per 
cent 

Per 

cent 

Per 
cent 

Per 
cent 

Per- 
cent 

Per 
cent 

Per 
cent 

13.2 
16.7 
20.6 
26.3 
16.4 
14.6 
9.2 
20.5 

17.0 

15.8 
12.5 
21.9 
19.2 
11.0 
13.3 
17.2 
19.2 

17.0 

29.0 
29.2 
42.5 
45.5 
27.4 
27.9 
26.4 
39.7 

34.0 

42.0 
34.7 
43.6 
23.4 
35.6 
37.5 
51.1 
37.1 

30.0 

15.8 
9.7 
6.4 
8.9 
17.8 
17.3 
7.9 
8.2 

13.0 

57.8 
44.4 
50.0 
32.3 
53.4 
54.8 
59.0 
45.3 

43.0 

6.6 
5.5 
2.5 
8.9 
9.6 
9.3 
5.3 
6.8 

10.0 

4.0 
4.2 
2.5 
8.9 
5.5 
5.3 
5.3 
5.5 

8.0 

2.6 
9.7 
2.5 
4.4 
4.1 
2.7 
4.0 
2.7 

5.0 

13.2 
19.4 
7.5 
22.2 
19.2 
17.3 
14.6 
15.0 

23.0 

Buffalo. 

7 

Kansas  City- 
Louisville 

New  York 

St.  Louis 

Richardson's 
Ideal 

aCompiled    from    Richardson's    Modern    Sheet    Asphalt    Pavement,    p.    331,    1913,    by 
Baker,   I.   O.,   op.   cit.,   p.    426. 

be  stated  as  a  general  fact  because  successes  and  failures  have  been  recorded 
with  both  classes  of  sand".4  The  size  of  sand  used  is  very  essential  to  the 
most  satisfactory  results  from  a  pavement.  Table  5  shows  the  standard 
gradings  for  sand  for  the  wearing  course  of  sheet  asphalt  pavements  and 
Table  6  some  of  the.  gradings  of  sand  actually  used  for  paving  in  various 
cities  by  the  Barber  Asphalt  Company. 


ASPHALTIC  CONCRETE  PAVEMENTS 

This  pavement  consists  of  a  concrete  foundation  with  a  wearing  course 
of  asphaltic  concrete,  composed  of  asphalt  cement  and  broken  stone  with  or 
without  sand.  It  is  desirable  that  sand,  if  used  in  this  type  of  pavements,  be 
free  from  impurities  such  as  shale  or  clay,  and  consist  of  clean,  hard  grains. 
The  grading  of  the  sand  should  be  approximately  the  same  as  for  the  wearing 
course  of  sheet  asphalt  pavement. 


4Agg,    T.   PL,    The   construction   of   roads   and    pavements,    2d    ed.,    p.    306,    New  York 
McGraw  Hill  Book  Co.,   1920. 


104  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

ASPHALT  BLOCK  PAVEMENTS 

This  type  of  pavement  consists  of  blocks  of  prepared  asphalt  laid  on  a 
foundation  of  concrete,  macadam  or  gravel.  The  blocks  are  12  by  5  by  3  to  5 
inches  in  size  and  are  made  by  compressing  in  molds  a  mixture  similar  to  that 
used  for  making  the  wearing  course  of  sheet  asphalt  pavement.  However, 
sand  is  not  used  by  some  manufacturers  of  asphalt  blocks  as  it  is  reported  to 
cut  the  molds.5 

Sand  for  Asphaltic  Flooring 

Asphaltic  flooring  made  of  sand,  a  fine  filler  and  an  asphalt  mastic,  is  sold 
under  various  trade  names.  When  this  type  of  flooring  is  to  be  used  in  gov- 
ernment buildings,  the  sand  aggregate  must  meet  the  following  specifications 
issued  by  the  Federal  Specifications  Board : 

"The  mineral  aggregate  shall  be  sand  and  small  gravel.    It  shall  be  clean. 

hard  grained  and  free  from  clay,  silt,  organic  and  other  foreign  matter,  and 

shall  be  properly  graded  from  coarse  to  fine,  so  as  to  produce  a  mixture  of 

greatest  density  and  stability.    It  shall  fall  within  the  following  limits : 

Per  cent 

Passing  a  No.  3  screen 100 

Total  passing  a  No.       8  screen,  not  over 60 

Total  passing  a  No.     30  screen,  not  over 40 

Total  passing  a  No.  100  screen,  not  over 7.5" 

Backing  Sand  (See  molding  sand,  pp.  125-130) 

Sand  as  a  Ballast  for  Ships 

Sand  is  sometimes  carried  by  ships  as  ballast.  The  most  desirable  feature 
such  sand  can  possess,  is  that  it  be  of  commercial  value  at  the  port  of 
discharge. 

Banding  Sand 

Banding-  sand  is  the  name  applied  to  a  special  type  of  abrasive  sand.  It  is 
used  to  some  extent  for  grinding  plate  glass  but  its  most  important  use  is  for 
beveling  the  edges  of  plate  glass. 

Like  any  other  abrasive  sand,  banding  sand  should  consist  of  tough,  hard, 
durable  grains,  and  should  be  free  from  impurities  and  foreign  material.  The 
grains  may  be  rounded  or  angular.  The  sand  should  be  well  graded.  A 
Pennsylvania  glass  company  specifies  that  banding  sand  be  a  high  silica  sand, 
white  in  color  and  of  such  size  that  98  per  cent  will  pass  30  mesh,  20  per  cent 
be  retained  on  60  mesh,  50  per  cent  on  120  mesh,  and  20  per  cent  on  200  mesh 

The  St.  Peter  sandstone  makes  a  very  suitable  banding  sand  and  is  com- 
monly  used  and  sold  for  that  purpose. 

5Richardson,    Clifford,    The   modern   asphalt   pavement,   p.    29,   New  York,   J.   Wiley   & 
Sons,  1913. 


USES  OF  SAND  105 

Sand  Bedding  for  Stock  Cars 

Sand  for  this  purpose  should  be  free  from  clay  and  pebbles,  and  be  open 
enough  to  permit  ready  drainage. 

Bird  Grit  (See  poultry  grit,  p.  134) 
Brass  Sand 

In  making  molds  for  casting  brass,  bronze  and  aluminum,  a  very  fine 
sand,  known  commercially  as  brass  sand,  is  used.  The  chief  requirements  of 
this  sand  are  that  it  be  very  fine  and  sufficiently  refractory  to  withstand  the 
temperatures  involved  in  casting.  Since  these  temperatures  are  less  than 
those  to  which  steel  molding  sands  are  subjected,  fine  St.  Peter  is  a  suit- 
able sand. 

Sand  for  Clay  Brick 

Sand  is  used  as  a  constituent  of  clay  bricks  to  prevent  contraction,  shrink- 
age and  cracking  during  burning  and  cooling  and  to  give  the  brick  a  durable 
surface.  It  is  also  used  for  molding,  facing  and  setting  brick.  (See  parting, 
facing  and  setting  sand,  pp.  131,  113,  139.) 

Sand  for  clay  brick  should  in  general  be  between  30  and  120  mesh6  and 
well  graded.  Both  angular  and  rounded  sands  are  used,  though  the  former 
are  generally  preferred.  The  sands  should  be  free  from  soluble  salts  which 
will  cause  fusion  of  the  brick  during  burning  or  efflorescence  after  burning. 
They  should  also  be  free  from  any  substances  which  will  give  the  brick  an 
undesirable  color. 

The  St.  Peter  sand  is  produced  clean  and  in  graded  sizes  and  is,  there- 
fore, well  suited  for  use  in  clay  brick. 

Sand  for  Brick  Molding 

Sand  is  used  for  dusting  or  sanding  brick  molds  to  prevent  the  brick 
from  sticking  to  the  molds. 

Such  sand  should  be  fine,  and  free  from  clay.  When  used  for  sanding 
molds  for  silica  brick  it  is  essential  that  it  should  not  differ  radically  in 
chemical  composition  and  physical  characteristics  from  the  brick. 

Because  of  its  refractoriness  and  cleanness,  and  also  because  it  can  be 
secured  in  well-sized,  fine  grades,  the  St.  Peter  sand  is  very  suitable  for  brick 
molding.  One  company  using  St.  Peter  sand  for  sanding  molds  in  the 
manufacture  of  silica  brick  requires  sand  which  will  meet  the  following 
specifications : 


eSearle,  A.  B.,  Sands  and  crushed  rocks,  vol.   2,  p.   3,  London,   1923. 


106  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

Size  of  grain 100  per  cent  must  pass   a  20-mesh  sieve 

Not  more  than  10  per  cent  shall  pass  a  100-mesh  sieve 

Color Preferably  white   or   buff 

Shape   of  grains Round 

Per  cent 

Chemical   analysis Silica Minimum    permissible    97.5 

Alumina Maximum   permissible   0.5 

Lime Maximum    permissible    0.5 

Magnesia Maximum   permissible   0.5 

Iron  oxide Maximum    permissible   0.5 

Loss  on  ignition-Maximum   permissible   1.0 

Melting  point Minimum    permissible 3065°  F.    (1685°  C.) 

Orton  cone  31. 

Sand  for  Silica  Brick 

Most  silica  brick  are  made  from  crushed  quartzite  or  crushed  flint, 
bonded  by  clay  or  lime.  The  chief  objection  to  sands  for  this  purpose  is  that 
they  are  often  too  low  in  silica  content  and  too  fine  grained,  and  contain  an 
excess  of  fluxing-  impurities.  Three  types  of  refractory  brick  are  made,  of 
which  sand  is  one  of  the  principal  constituents,  namely  sand-brick,  semi-silica 
brick  and  sand-bauxite  brick.7  These  bricks  are,  however,  only  moderately 
refractory.  Sand  for  refractory  brick  should  contain  from  96  to  98  per  cent 
silica  and  should  be  free  from  organic  material  and  dirt.8  The  total  amount 
of  alkalies  present  should  not  commonly  exceed  2  per  cent.  Small  amounts  of 
iron  and  alumina,  if  the  latter  occurs  as  clay,  are  not  harmful.9 

Sand  for  Sand-lime  Brick10 

Sand-lime  bricks  are  made  by  mixing  about  nine  parts  of  sand  with  one 
part  of  slaked  lime,  pressing  the  resulting  mixture  into  bricks  and  curing  them 
in  steam.  A  chemical  reaction  occurs  between  the  sand  and  the  lime  and  pro- 
duces hydrated  calcium  silicate,  which  is  the  bond  of  the  brick. 

Sand  for  sand-lime  brick  should  consist  of  both  rounded  and  angular 
particles  and  should  be  composed  of  grains  of  various  sizes.  About  15  per 
cent  of  the  sand  should  pass  a  100-mesh  sieve.  Clay  when  not  in  excess  of 
10  or  12  per  cent  is  generally  not  injurious  to  the  brick,  but  for  most  sand- 
lime  brick,  a  clean,  siliceous  sand  is  preferred. 

The  St.  Peter  sand  is  well  suited  for  use  in  the  manufacture  of  sand- 
lime  brick  because  it  consists  of  quartz  grains,  both  angular  and  rounded,  and 
can  be  obtained  in  graded  sizes. 


7Searle,  A.  B.,  op.  cit.,  pp.   144  and  145. 

8ldem,  p.   147. 

oAdditional  references  are  : 

Moore,   E.   S.,   and   Taylor,   T.   G.,   The   silica  refractories   of  Pennsylvania  :   Penn- 
sylvania Geological   Survey,   4th   ser.,   Bull.   M3,   1924. 
Ross,    D.    W.,    Silica   refractories :   U.    S.    Bur.    Standards,    Technologic   Paper    116, 
1919. 
loSand-lime   brick,    description   and   specification :   U.    S.   Bur.    of   Standards,    Circular 
109,   p.   4,   1921. 

Parr,    S.    W.    and    Ernest,    T.    R.,    A    study    of    sand-lime    brick :    Illinois    State    Geol. 
Survey  Bull.   18,   p.   42,   1912. 


USES   OF  SAND  107 

Brick  Pavements 
general  statement 

The  two  types  of  brick  pavements  now  in  use  are  known  as  "monolithic" 
and  "semi-monolithic".  The  latter  type  consists  of  a  cement  concrete  base  or 
foundation,  a  bedding  course  of  sand  or  sand-cement,  and  the  wearing  course 
of  brick.  The  joints  between  the  bricks  are  filled  with  sand,  a  grout  of 
cement  and  sand,  or  a  bituminous  filler.  The  monolithic  type  consists  of  a 
base  course  of  concrete  into  which  the  brick  are  laid  and  pressed  before  it  sets. 
Cement  mortar  is  used  as  grout. 

The  specifications  for  sand  used  in  both  types  of  brick  pavements  are 
essentially  the  same  and  will  be  described  without  reference  to  the  type  of 
pavement. 

CEMENT    CONCRETE   BASE 

Sand  enters  into  this  part  of  the  pavement  only  in  the  fine  aggregate 
most  of  which  is  quartz  sand ;  it  may  also  be  rock  screenings.  The  sand 
should  consist  of  clean,  uncoated,  hard,  durable  grains  and  be  free  from 
organic  material,  friable  fragments,  such  as  shale  or  slate,  and  "shall  not  con- 
tain clay  or  silt  in  excess  of  five  per  cent  by  weight".11  The  specifications  of 
the  Illinois  Division  of  Highways12  are  a  little  more  stringent  and  require  that 
the  "fine  aggregate  shall  not  contain  over  two  (2.0)  per  cent  of  material 
removed  when  tested  by  the  Elutriation  test." 

The  Illinois  Highway  Department  specifies  further  that  not  less  than  95 
per  cent  should  pass  a  %-inch  sieve ;  not  less  than  35  per  cent  or  more  than 
70  per  cent  20  mesh ;  not  more  than  20  per  cent  50  mesh ;  and  not  more  than 
5  per  cent  100  mesh. 

BEDDING   COURSE 
SAND 

The  sand  bedding  course  consists  of  a  layer  of  sand  between  y2  and  1 
inch  thick  when  finished,  onto  which  the  brick  making  the  wearing  surface 
are  laid.  Sand  for  this  purpose  "shall  not  exceed  one-quarter  inch  in  maxi- 
mum grain  size.  It  may  contain  fine  material  passing  a  No.  20  standard  mesh 
sieve,  not  exceeding  fifteen  per  cent  by  weight."11  This  fine  material  may  be 
loam  or  clay.  The  specification  of  the  Illinois  Division  of  Highways  for 
bedding  sand  is  the  same  as  that  for  fine  aggregate. 

SAND-CEMENT 

The  sand-cement  bedding  course  consists  of  a  layer  of  dry  sand  and 
Portland  cement  mixed  in  the  ratio  of  1  to  4.    The  laver  when  finished  should 


nSpecifications,   National  Paving  Brick  Manufacturers  Assoc,   1924. 
i2Standard  specifications  for  road  and  bridge  construction,   Illinois  Division  of  High- 
ways,  pp.    28,    63,    67,   Nov.    1,    1924. 


108  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

be  between  y2  and  1  inch  thick.  The  brick  are  set  on  this  sand-cement  bed 
and  the  pavement  is  then  sprinkled.  Sufficient  water  trickles  between  the 
brick  to  wet  the  sand-cement  bed  and  to  cause  it  to  set.  Sand  for  this  purpose 
should  pass  a  ^-inch  sieve,  be  of  uniform  size,  and  clean.  It  should  be  "free 
from  soft,  friable  material,  shale  or  slate,  vegetable  or  other  organic  matter. 
It  shall  not  contain  clay  or  silt  in  excess  of  five  (5)  per  cent  by  weight."11 

JOINT  FILLER 


Sand  for  this  purpose  must  be  clean,  dry,  free  from  flaky  particles  and 
"of  such  sizes  that  all  will  pass  a  No.  12  sieve".11 

CEMENT   GROUT 

Cement  grout  filler  consists  of  1  to  2  or  1  to  3  parts  of  Portland  cement 
and  sand  respectively.  Sand  used  in  cement  grout  should  consist  of  clean, 
hard,  sharp,  uncoated  grains  and  should  not  contain  "more  than  two  (2)  per 
cent  of  material  which  may  be  removed  by  the  Elutriation  test".12  Other 
specifications  state  that  the  sand  shall  not  contain  clay  in  excess  of  five  (5) 
per  cent.  The  Illinois  Highway  Department  specifies  that  the  sand  shall  be 
well  graded  from  coarse  to  fine  and  that  "not  less  than  95  per  cent  shall  pass 
a  10  mesh  sieve,  not  less  than  75  per  cent  20  mesh,  not  more  than  30  per  cent 
50  mesh,  and  not  more  than  10  per  cent  100  mesh".12  The  National  Paving 
Brick  Manufacturers  Association  recommends  sand  of  such  size  that  "100  per 
cent  will  pass  a  No.  12  sieve,  not  more  than  40  per  cent  a  No.  50  sieve,  and 
not  more  than  6  per  cent  a  No.  100  sieve".11 


This  type  of  filler  may  be  tar  or  asphalt.  Sand  is  not  commonly  employed 
but  it  is  used  merely  to  surface  the  filled  joints  to  prevent  the  bitumen  from 
sticking  to  the  wheels  of  passing  vehicles.  Sand  which  passes  inspection  as 
fine  aggregate  is  used. 

ST.   PETER  SAND  FOR  USE  IN  BRICK   PAVEMENTS 

The  St.  Peter  sand,  except  when  badly  coated  with  iron  hydroxide,  will 
furnish  a  high-grade  paving  sand.  It  possesses  inherently  the  very  desirable 
properties  of  cleanness  and  hardness,  and  though  some  parts  of  the  formation 
are  probably  a  little  too  fine,  the  sand  of  the  deposit  as  a  whole  is  of  such  size 
as  to  pass  the  specifications  stated  above. 

Burnishing  Sand13 

For  rolling  down  and  burnishing  gold  decorations  on  china  and  porce- 
lain, a  fine-grained,  high  silica  sand  called  "burnishing  sand"  is  employed. 


isstone.  R.  W.,  Sand  and  gravel:  U.   S.   Geol.   Survey  Mineral  Resources,   1912,  pt.   2, 
p.    630,    1913. 


USES   OF   SAND  109 

This  type  of  sand  should  consist  of  clean,  tough,  rounded  grains.  The  sand 
used  commercially  is  uniform  in  size  and  practically  all  of  it  passes  65  mesh 
but  is  retained  on  100  mesh. 

Sand  for  the  Manufacture  of  Carborundum 

Chemically,  carborundum  is  known  as  silicon  carbide.  It  is  made  by 
fusing  sand,  coke,  sawdust  and  salt  in  an  electric  furnace.  The  sand  makes 
up  about  half  of  the  furnace  charge  and  the  coke  about  a  third.  The  chemical 
equation  describing  the  principal  reaction  taking  place  in  the  furnace  is  as 
follows : 

Si02  (sand)  -f-  3C  (coke)  ->-  SiC  (silicon  carbide)  -|-  2CO 

The  most  important  specification  for  sand  to  be  used  in  making  carbo- 
rundum is  that  it  be  a  high  silica  sand.  The  sand  should,  therefore,  be  free 
from  clay,  organic  material  and  other  impurities.  The  shape  of  the  grains  is 
unimportant.  It  is  desirable  that  the  sand  be  graded  to  remove  lumps  and 
overly  large  grains.  One  company  specifies  that  sand  for  carborundum  be 
white,  contain  over  99.5  per  cent  silica  and  be  of  such  size  that  100  per  cent 
will  pass  24  mesh  and  100  per  cent  be  retained  on  128  mesh. 

The  high  silica  content  of  the  St.  Peter  sandstone  makes  it  very  desirable 
for  use  in  the  manufacture  of  carborundum. 

Sand  for  Cements14 

Sand  is  used  in  the  following  types  of  cements;  its  function  is  chiefly 
that  of  an  inert  filler. 

Sand  cement — an  intimate  mixture  of  sand  and  cement  made  by  grinding  the 

two  together. 

Oxychloride  cement a  mixture  of  fine  sand  and  magnesium  oxychloride. 

Borax  cement a  mixture  of  fine  sand  and  borax. 

Lead  cements a  mixture  of  sand  with  white  lead  or  litharge,  lime  or  plaster 

of  Paris,  and  linseed  oil. 
Dental  cement a  mixture  of  ground  sand,  zinc  oxide,  borax,  and  zinc  chloride. 

No  specifications  are  available  for  the  sand  used  in  the  cements  enu- 
merated above,  but  in  general  a  high  silica  sand,  ground  to  100  or  200  mesh 
is  used. 

Sand  for  Chemical  Purposes 

Sand  is  used  in  the  preparation  of  a  number  of  chemical  compounds  other 
than  those  mentioned  specifically  elsewhere  in  the  text.  In  general  it  should 
be  fine-grained  and  very  pure. 

i4Eckel,  E.  C,  Cements,  limes  and  plasters  ;  their  materials,  manufacture,  and  prop- 
erties, 2d  ed.,  p.  537,  New  York,  J.  Wiley  &  Sons,  1922. 

Searle,   A.   B.,   Sands  and  crushed  rocks,  vol.   2,  p.   42,  London,   1923. 


110  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

Coking  Sand15 

In  the  manufacture  of  coke,  sand  is  sometimes  added  to  the  charge  of  the 
retorts  or  ovens  to  combine  with  any  bases  present.  Sand  for  this  purpose 
should  be  fine  and  high  in  silica. 

Sand  for  Concrete 

In  general,  sand  consisting  principally  of  quartz  grains  is  used  as  the  fine 
aggregate  for  concrete.  Specifications  for  sand  for  this  purpose  vary  some- 
what but  agree  that  it  should  be  clean,  free  from  oily  or  organic  matter,  dust, 
earth,  clay,  shale  particles,  mica,  ochre  or  other  soft  grains,  and  shall  consist, 
of  hard,  strong,  uncoated  grains.  Specifications  also  require  that  a  1 :2  to  1 :3 
mortar  made  of  Portland  cement  and  the  sand  shall  have  a  compressive 
strength  at  the  end  of  seven  and  twenty-eight  days  respectively,  at  least  equal 
to  that  of  a  mortar  made  from  the  same  cement  and  Ottawa  standard  sand. 

The  following  specifications  give  an  idea  of  the  variation  permitted  in  the 
size  of  the  grains  composing  the  fine  aggregate. 
Illinois   Highway  Department10 

Passing  54-inch   sieve not  less  than     95% 

Passing     20-mesh  sieve 35   to     70% 

Passing     50-mesh  sieve not  more  than     20% 

Passing  100-mesh  sieve not  more  than       5% 

California  Highway  Engineers17 

Passing  a  ^-inch   sieve    100% 

Passing  a  No.   3  sieve not  less  than     95% 

Passing  a  No.  4  sieve 85  to     95% 

Passing  a  3 0-mesh   sieve 15   to     3 5  % 

Passing  a   100-mesh  sieve,   including  silt   and   clay not  more  than        5% 

Engineers  Society  of  Western  Pennsylvania18 
Fine  sand: 

Not  over     0%  shall  be  retained  on  a  No.  4  sieve 

Not  over  15%  shall  be  retained  on  a  No.  8  sieve 

At  least  85%  shall  be  retained  on  a  No.     50  sieve 

At  least  94%  shall  be  retained  on  a  No.  100  sieve 
Coarse  sand: 

not  over       9%  shall  be  retained  on  a  ^-inch  sieve 

Not  over  15%  shall  be  retained  on  a  No.  4  sieve 

At  least  70%  shall  be  retained  on  a  No.     50  sieve 

At  least  94%  shall  be  retained  on  a  No.  100  sieve 
Tyler    Standard    Sieves    to    be    used.      Weight    removed    by    decantation    test    made 
according   to    A.    S.    T.    M.    method.      Serial    Designation    D    136-22T,    shall    not 
exceed    3%. 

Because  of  the  inherent  hardness  and  cleanness  of  the  grains  of  the  St. 
Peter  sand,  except  where  badly  stained  by  iron,  it  is  very  satisfactory  for  con- 


]5Searle,   A.   B.,    op.    cit,   p.    228. 

^Standard  specifications  for  road  and  bridge  construction,  Illinois  Division  of  High- 
ways,  Nov.    1,    1924. 

i7McKesson,  C.  L.,  Materials  and  research  engineer  for  the  California  Highwav 
Commission),  Standardization  of  Specifications  for  sand,  rock  and  gravel:  Rock  Products, 
vol.    28,   No.    4,   p.    62,   Nov.    28,    1925. 

isTentative  specifications  for  aggregates,  Civil  Section  of  the  Engineers  Society  of 
"Western  Pennsylvania,  Sept.   17.   1925. 


USES   OF  SAND  111 

crete  work.  As  it  occurs  naturally  it  rarely  contains  more  than  the  permissible 
amount  of  clay,  but  some  of  it  is  a  little  too  fine  to  meet  specifications.  Inas- 
much as  the  sand  is  produced  commercially  in  sizes  which  meet  specifications, 
it  is  readily  available  for  concrete  purposes. 

Core  Sand  (See  molding  sand,  pp.  125-130) 

Sand  for  Cuspidors 

Earthenware  jars  filled  with  white  sand  are  used  in  many  hotels  and 
public  buildings  as  waste  receptacles  and  cuspidors.  The  principal  require- 
ment of  the  sand  used  for  this  purpose  is  that  it  be  white  and  clean.  The  St. 
Peter  sand  is  admirably  suited  inherently  for  this  purpose  and  is  widely  used. 

Cutting  and  Sawing  Sand 

Sand  is  commonly  used  as  an  abrasive  in  cutting  and  sawing  stone.  It  is 
applied  with  water  directly  to  the  cutting  or  sawing  blade. 

DESIRABLE  PROPERTIES 

1.  It  is  desirable  that  the  grains  be  of  approximately  the  same  size,  or 
within  a  given  size  range,  in  order  that  the  maximum  cutting  efficiency  may 
be  secured.  If  the  grains  are  of  unsorted  sizes,  the  larger  grains  alone  sup- 
port the  cutting  edge  of  the  blade  and  do  the  cutting  work,  whereas  the  smaller 
grains  are  practically  inert,  and  may  possibly  be  detrimental  to  obtaining 
maximum  speed  in  cutting. 

The  texture  of  the  sand  used  varies  with  the  preferences  of  different 
consumers  and  is  probably  partly  dependent  on  the  texture  of  local  supplies. 
One  marble  company  using  St.  Peter  sand  specifies  a  sand  which  will  pass 
30  mesh  and  be  retained  on  50  mesh.  Another  marble  company19  uses  washed 
river  sand  of  which  3.7  per  cent  is  retained  on  10  mesh;  12.6  per  cent  on  20 
mesh;  83.8  per  cent  on  48  mesh;  and  98.6  per  cent  on  100  mesh.  Still 
another  analysis19  of  sawing  sand  shows  0.4  per  cent  retained  on  20  mesh ; 
79.6  per  cent  on  35  mesh ;  and  99.6  per  cent  on  65  mesh.  A  stone  plant  in 
Illinois  specifies  the  following  for  cutting  and  sawing  sand :  75  per  cent  should 
pass  30  mesh,  and  85  per  cent  to  be  retained  on  40  mesh.  And  finally  the 
Bedford  Stone  Club  representing  the  Bedford  stone  industry  of  Indiana 
specifies,  "hard,  white  silica  sand,  thoroughly  washed  and  free  from  all  for- 
eign matter ;  dried  and  screened  so  as  to  remove  all  dust  and  fine  particles ; 
and  testing  between  80  and  85  per  cent,  remaining  on  a  40-mesh  screen".20 

2.  The  shape  of  the  sand  grains  used  is  also  a  matter  of  preference  and 
of  the  character  of  the  grains  of  local  supplies  of  sand.     Both  angular  and 


lOWeigel,  W.  M.,  Special  sands:  U.  S.  Bur.  Mines,  Serial   2646,  October,   1924. 
2oPersonat  communication,  Dec,  1924. 


112  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

rounded  sands  are  used;  some  companies  state  that  they  prefer  the  rounded 
grains  and  others  the  angular  grains. 

3.  In  a  pure  quartz  sand  all  the  sand  grains  will  be  of  about  the  same 
hardness.  If  grains  of  other  minerals  besides  quartz  are  present  in  the  sand, 
they  should  be  of  a  hardness  equal  to  or  greater  than  that  of  quartz.  Softer 
material  is  of  doubtful  value  and  may  possibly  be  harmful.  A  quartz  sand  is 
generally  preferred. 

4.  The  color  of  a  sand  is  not  generally  essential  provided  that  the  color- 
ing material  will  not  stain  or  result  in  stains  in  the  stone  being  worked. 

5.  The  sand  grains  should  be  hard  and  free  from  incipient  fractures 
which  might  result  in  easy  breakage  of  the  grains. 

6.  The  sand  should  be  free  from  clay  and  organic  material  since  these 
are  of  no  value  and  may  cause  clogging  of  feed  pipes. 

7.  The  chemical  analysis  of  cutting  and  sawing  sand  is  not  generally 
important  except  as  it  shows  the  approximate  quartz  content  of  the  sand  and 
suggests  what  minerals  are  present  as  impurities. 

ST.  PETER  SAND  AS  CUTTING  AND  SAWING  SAND 

The  St.  Peter  sand  is  extensively  used  as  cutting  and  sawing  sand.  After 
it  has  been  washed  and  screened,  it  possesses  all  the  desirable  properties  of 
sand  for  this  purpose. 

Sand  for  Dental  Purposes 
Ground  sand  or  silica  is  used  by  dentists  as  a  detergent  or  abrasive. 

Sand  for  Dispelling  Fog21 

The  United  States  government  is  experimenting  with  electrically  charged 
sand  scattered  by  aeroplanes  as  a  means  of  dispelling  fogs  and  clouds  over 
harbors.  The  sand  used  is  120-mesh  silica  sand.  It  is  claimed  that  two  large 
planes  could  eliminate  fog  over  an  area  of  117  square  miles  or  more. 

Sand  for  Enameling22 

In  the  preparation  of  enamels  for  applications  to  metal  objects,  quartz 
sand  and  ground  quartz  sand  are  used  as  constituents  and  sometimes  as  a 
partial  substitute  for  feldspar.  The  sand  is  commonly  used  in  the  preliminary 
or  "ground"  coat  given  the  metal  and  the  ground  quartz  sand  in  the  finish 
or  "cover"  coat.  The  use  of  quartz  in  the  proper  proportion  in  an  enamel  is 
said  to  give  it  additional  hardness  and  resistance  to  attack  by  acids. 


2iThe  newest  use  for  fine  sand  :  Roek  Products,  vol.  27,  No.   24,  p.  55,  Nov.   29,  1924. 
22Grunwald,  J.,  Raw  materials  for  the  enamel  industry,  p.   16,  London,  1914. 
Stanley,   H.   F.,   Materials   and   methods   used  in   the   manufacture   of  enameled   cast- 
iron  wares:  U.   S.   Bur.   Standards,  Technologic  Paper  142,  pp.    20-22,   1919. 


USES  OF   SAND  113 

Sand  to  be  used  in  enamels  should  be  free  from  clay  and  contain  more 
than  97  per  cent  silicon  dioxide  (silica).  It  should  not  contain  more  than 
0.32  per  cent  ferric  oxide,  since  iron  imparts  a  color  to  the  enamels  which  is 
undesirable.  For  the  ground  coat  a  sand  comparable  in  size  to  a  high-grade 
glass  sand  is  commonly  preferred.  Finely  pulverized  sand  is  used  for  making 
the  cover  enamels. 

Because  of  its  purity  and  because  it  is  produced  in  sizes  suitable  for  use 
in  making  enamels,  the  St.  Peter  sand  is  well  adapted  for  this  purpose. 

Engine  Sand 

Engine  sand  is  used  to  increase  the  traction  of  and  so  prevent  slipping 
of  the  driving  wheels  of  railroad  locomotives,  electric  cars,  and  mine  locomo- 
tives. It  is  also  known  as  traction  or  trolley  sand.  It  is  applied  to  the  rails 
from  a  pipe  connected  to  the  sand  dome  or  box. 

So  far  as  could  be  ascertained,  there  are  no  detailed  specifications  for 
engine  sand.  Four  railroad  companies  to  whom  inquiries  were  sent  replied 
that  they  had  no  specifications  for  the  sand.  The  matter  of  prime  importance 
is  commonly  the  availability  of  the  commodity  to  the  supply  point  of  the  con- 
sumer. It  is  important,  however,  that  engine  sand  be  clean  and  dry.  In 
general  a  rather  uniformly  graded,  medium  fine  sand  is  preferred.  The  sand 
should  be  free  from  small  twigs,  leaves  and  other  foreign  matter  which  might 
clog  the  sand  pipe  or  valve,  and  should  not  contain  large  amounts  of  clay  or 
other  material  which  might  absorb  moisture  and  thus  tend  to  form  lumps  in 
the  sand.  A  high  silica  sand  is  generally  desirable.  Both  rounded  and  angular 
sands  are  used. 

Since  the  St.  Peter  sand  is  composed  of  hard,  durable  grains  and  can  be 
purchased  clean  and  dry  in  well-graded  sizes,  it  makes  a  very  satisfactory 
engine  sand  and  is  rather  commonly  used  in  Illinois,  at  least,  for  this  purpose. 

Sand  for  Erasers 
Sand  is  used  as  an  abrasive  in  certain  types  of  rubber  erasers  for  rapid, 
rough  work.    A  fine,  angular,  sharp  sand  is  desirable  for  this  purpose. 

Sand  for  Explosives23 
Sand  is  sometimes  used  as  an  absorbent  for  nitroglycerine  in  the  manu- 
facture of  dynamite  and  other  nitroglycerine  explosives.    Any  common  sand 
which  is  composed  of   rounded  grains  of   uniform   size  and  which  is   fine 
enough  to  pass  a  30-mesh  sieve  is  suitable  for  this  purpose. 

Facing  Sand  and  Silica  Mold  Wash  for  Foundry  Use 
In  order  to  give  castings  a  smooth  surface,  molds  are  commonly  dusted 
or  washed  with  fine  silica.     In  making  very  high-grade  castings,  sand  as  fine 

23Searle,   A.   B.,    Sands  and   crushed   rocks,   vol.    2,   p.    236,   London,    1923. 


114  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

as  250  mesh  is  sometimes  used.  The  practice  is,  however,  to  use  as  coarse  a 
sand  as  is  consistent  with  the  character  of  the  casting  and  surface  desired,  in- 
asmuch as  very  fine  facing  sand  tends  to  clog  the  surface  of  the  mold  and 
thus  decrease  its  permeability.  For  facing  molds  for  steel  castings  ground 
sand  passing  a  200-mesh  sieve  is  commonly  used.  St.  Peter  sand  is  widely 
used  as  a  mold  wash  and  facing  sand.  The  specifications  of  the  United  States 
Navy  Department  for  silica  mold  wash  are  as  follows : 

50S1 
Jan.   1, 
NAVY  DEPARTMENT  SPECIFICATIONS  1920 

SILICA  MOLD  WASH 
(for  Steel  Foundry  use) 
General    Instructions. 

1.  The  material  desired  under  these  specifications  is  a  pure  silica  flour,  very  finely 
powdered  and  air  floated  to  remove  such  particles  as  will  separate  in  a  water  emulsion. 
Chemical    Requirements. 

2.  The  powder  shall  show  an  analysis  not  less  than  99  per  cent  dehydrated  silica 
&(SiO„). 

Physical    Requirements. 

3.  100  per  cent  of  the  powder  shall  pass  through  a  sieve  having  200  meshes  to  the 
the    linear   inch. 

4.  A  5-gram  portion  shall  be  placed  in  a  100-cubic  centimeter  graduated  com- 
parison tube  and  the  volume  brought  to  100  cubic  centimeters  by  the  addition  of  cold 
water.  After  thorough  agitation  and  mixing,  1  cubic  centimeter  of  sediment  shall  settle 
to  the  bottom  of  the  tube  in  not  less  than   10  minutes. 

General    Requirements. 

5.  The  material  shall  be  suitable  for  use  in  steel  foundry  work  by  mixing  with 
water  ot  binder  mixture  for  washing  the  surfaces  of  sand  molds. 

Samples. 

6.  Bidders  shall   supply  samples  of  material  they  propose   to  furnish. 
SPECIFICATIONS,   WHERE   OBTAINABLE. 

Note. — Copies   of  the   above   specifications   can  be   obtained   upon   application  to 
the  Bureau  of  Supplies  and  Accounts,  Navy  Department,  Washington,  D.   C. 
References. 

Comdt.  &  Supt.  Nav.  Gun  Factory,  Nov.  8,   1919. 
S.   &  A.,   380-1411 
149559—19 

Washington:     Government  Printing  Office:   1919 

Sand  for  Facing  Tile  and  Brick 

In  order  to  obtain  certain  architectural  or  artistic  effects,  some  face-brick 
and  roofing  tile  are  given  a  face-coat  of  sand.  The  sand  is  applied  to  the 
brick  or  tile  before  burning. 

In  general  the  size  of  the  sand  used  for  facing  brick  and  tile  depends  on 
the  preference  of  the  maker.  A  medium  sized  sand  is  very  commonly  used. 
If  the  brick  or  tile  is  red  it  is  desirable  that  a  small  amount  of  iron  oxide  be 
present  in  the  sand  so  that  it  will  be  red  after  burning  and  match  the  brick.  If 
a  white  brick  is  being  manufactured,  however,  the  sand  should  be  free  from 
iron  compounds  which  might  discolor  the  brick  either  during  burning  or  when 
in  the  wall. 

The  St.  Peter  sandstone  furnishes  various  grades  of  sand,  some  of  which 
contain  sufficient  iron  to  burn  red  or  yellow;  the  washed  product  burns  white. 


USES   OF   SAND  115 

Sand  for  Making  Ferro-silicon  and  Other  Silicon  Alloys24 

Ferro-silicon  is  made  by  heating  a  charge  of  quartzite  or  sand,  carbon 
(coke,  anthracite  or  charcoal)  and  iron  or  steel  turnings  in  an  electric  furnace. 
The  reaction  is  as  follows : 

SiO2  +  2C  +  Fe  ->  (Fe.Si)  +  2CO 
Other  alloys  are  made  in  the  same  way  by  substituting  other  metals  for  part 
of  the  silica  and  iron. 

The  chief  specification  for  sand  to  be  used  for  making  silicon  alloys  is 
that  it  be  fine,  free  from  foreign  material  and  more  than  95  per  cent  silica.  In 
general  lime  and  alumina  are  to  be  avoided.  Because  the  St.  Peter  sand  is 
chemically  very  pure  and  can  be  produced  in  fine  sizes,  it  should  be  suitable 
for  the  manufacture  of  silicon  alloys. 

Sand  as  a  Fertilizer  Filler 

Because  of  its  inherent  loose  and  incoherent  character,  sand  is  used  as  a 
filler  for  fertilizer.  The  sand  prevents  hardening  and  keeps  the  fertilizer  in 
a  mealy  condition.  No  specifications  are  known  for  sand  for  this  purpose 
but  it  seems  probable  that  any  clean,  medium  or  fine  sand  would  be  suitable. 

Sand  as  a  Filler 

Sand,  usually  in  the  ground  form,  is  used  as  a  filler  for  rubber,  paper, 
soap  and  linoleum.  It  is  also  used  for  filling  defects  in  the  surface  of  wood 
prior  to  finishing  painting,  when  it  is  commonly  mixed  with  a  small  amount 
of  oil  as  a  binder. 

Sand  for  Filling  Mines 

Sand  is  sometimes  used  for  filling  parts  of  worked  out  portions  of  mines 
to  prevent  the  collapse  of  the  mine  roof.  No  specifications  are  available  for 
sand  for  this  purpose. 

Filter  Sand 

The  growth  of  the  American  cities  and  the  consequent  necessity  of  an 
increased  supply  of  water  have  led  to  the  use  of  surface  water  to  fulfill  the 
demand.  The  sand  filter  is  commonly  employed  for  freeing  surface  water 
from  dirt,  organic  matter,  metallic  oxides  and  salts,  and  bacteria.  It  is  also 
used  for  removing  metallic  oxides  and  salts  from  well  waters.  A  sand  filter 
consists  of  layers  of  materials  of  different  sizes,  beginning  with  coarse  gravel 


24Martin,  Geoffrey,  Industrial  and  manufacturing  chemistry,  pt.  2,  Inorganic,  p.  407, 
New  York,    D.    Appleton   &   Company,    1918. 

Colony,  R.  J.,  High-grade  silica  materials  for  glass,  refractories,  and  abrasives : 
New  York   State  Museum   Bull.   Nos.    203,   204,   p.   26,   1917. 

Searle,  A.  B.,   Sands  and  crushed  rocks,  vol.   2,  p.   184,  London,   1923. 


116  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

at  the  bottom  and  grading  upward  to  the  sand  bed  which  is  at  the  top  of  the 
hlter.  Commonly  the  lower  12  or  18  inches  of  the  filter  is  composed  of  gravel 
layers,  and  the  upper  two  or  three  feet  of  sand. 

A  number  of  specifications  for  filter  sand  are  available.  Each  varies 
somewhat  from  the  others  but  the  following  items  are  essentially  the  same  for 
all  sets  of  specifications : 

1.  General  physical  properties — The  sand  shall  be  clean  and  free  from 
organic  material.  It  shall  consist  of  hard,  impermeable  grains,  either  rounded 
or  somewhat  angular  but  not  flat,  sharp,  or  splintery.  The  color  of  the  sand 
is  unimportant. 

2.  Size  of  grains — The  effective  size  (p.  155)  of  the  sand  may  vary 
from  0.3  to  0.7  but  for  municipal  work  is  usually  required  to  be  between  0.35 
and  0.45.  The  uniformity  coefficient  varies  between  1.5  and  2.0  but  is  or- 
dinarily about  1.6  for  sand  used  in  municipal  filters. 

3.  Chemical  properties — Filter  sand  should  be  composed  principally  of 
insoluble  grains.  This  property  is  tested  by  allowing  some  of  the  sand  to 
stand  for  24  hours  in  a  concentrated  solution  of  hydrochloric  acid.  The  loss 
in  weight  should  not  exceed  5  per  cent  and  commonly  a  loss  not  to  exceed  3 
per  cent  is  specified. 

The  St.  Peter  sand  of  the  Ottawa  district  has  long  been  used  as  a  filter 
sand.  The  physical  and  chemical  properties  of  the  sand  made  it  especially 
suited  for  this  purpose,  except  that  the  crude  sand  is  in  general  said  to  be 
somewhat  too  fine  to  be  an  ideal  filter  sand. 

Fire  Sand  (See  furnace  sand,  p.  117) 

Floor  Sand  (Sec  molding  sand,  pp.  125-130) 

Sand  as  a  Flux  in  Metallurgy 

Silica  sand  is  sometimes  used  in  the  smelting  of  sulphide  lead  and  copper 
ores  as  a  flux  which  will  combine  with  the  iron  present  to  make  a  slag.  It  is 
also  used  in  the  treatment  of  coarse  metal  copper  mattes  for  white  metal.23 

Inasmuch  as  the  silica  content  of  the  sand  is  of  first  importance,  it  is 
desirable  that  the  sand  for  metallurgical  purposes  be  a  high  silica  sand.  The 
size  of  the  grain  is  not  of  great  importance,  though  a  fine  sand  is  generally 
preferred.  Because  of  the  high  silica  content  and  fineness  of  grain  in  which 
the  St.  Peter  sand  can  be  produced,  it  is  a  very  high-grade  metallurgical  sand. 

French  Sand 

"French  sand  is  a  very  fine,  open,  sharp,  yellow  sand  imported  from 
France  used  for  making  molds  for  statuary,  brass  and  bronze  work".26 


25Schnabel,   Carl,  Handbook   of  metallurgy,   vol.   1,  pp.   140  and   284,   1808. 
26Stone,    Ft.    W.,   Sand  and   gravel:   IT.   S.   Geol.   Survey  Mineral   Resources   1912,   pt.   2. 
p.    631,    1913. 


USES    OF   SAND  117 

Friction  Sand 

Friction  sand  is  any  sand  used  for  the  purpose  of  creating  greater  friction 
between  two  objects.  The  term  is  used  synonymously  with  engine  sand,  but 
includes  also  sand  used  for  increasing  the  friction  between  pulleys  and  belts 
and  other  similar  devices.  A  rather  fine,  well  graded  sand  is  used  for  this 
purpose. 

Sand  for  Making  Fused  Silica27 

Fused  silica,  also  known  as  silica  glass  or  fused  quartz,  is  commonly  made 
from  crushed  crystalline  quartz.  However,  the  fusion  of  very  pure  silica 
sands  such  as  the  washed  St.  Peter  sand  gives  a  variety  of  fused  silica  which 
possesses  most  of  the  qualities  of  the  glass  made  from  the  crystalline  quartz 
except  that  numerous  small  bubbles  are  included  in  it.  The  glass  made  from, 
the  silica  sand  is  very  uniform  and  it  is  possible  that  it  may  find  considerable 
economic  application  because  it  is  not  permeable  to  liquids  or  gases  and  is  not 
affected  by  sudden  heating  and  cooling.  Crushed  fused  silica  is  coming  to  be 
of  increasing  interest  as  a  ceramic  material  and  it  is  possible  that  St.  Peter 
sand  will  be  an  acceptable  raw  material  for  manufacturing  fused  silica  for 
this  purpose. 

Furnace  and  Fire  Sand 

The  terms  furnace  sand  and  fire  sand  are  used  synonymously  to  describe 
sand  for  making  the  bottom  or  bed  of  metallurgical  furnaces  and  when  mixed 
with  small  amounts  of  fire  clay  or  lime  to  line  the  wralls.  Sand  for  these 
purposes  is  also  used  in  the  hearths  of  steel,  malleable  iron,  and  copper  fur- 
naces, and  with  a  binder  as  a  lining  for  converters,  cupolas,  and  ladles  for 
holding  molten  metal. 

The  chief  property  that  fire  sand  should  possess  is  high  refractoriness. 
Therefore,  a  high  silica  sand,  free  from  fluxing  impurities  and  organic  mate- 
rial is  desirable.  A  small  amount  of  clay  or  iron  hydroxide  which  may  serve 
as  a  bond  to  hold  the  sand  together  in  the  hearth  is  said  to  be  desirable.  The 
size  of  the  sand  used  seems  to  be  somewhat  arbitrary  and  to  depend  largely 
on  the  most  convenient  source  of  sand  supply.  The  material  is  generally  finer 
than  10  mesh,  however.  The  use  of  rounded  or  angular  sands  seems  also  to 
be  arbitrary.  Angular  sands  will  stand  at  a  somewhat  steeper  angle  in  the 
sides  of  the  furnace  bed  than  rounded  sands  but  do  not  make  as  compact  a 
bottom. 

The  St.  Peter  sand,  especially  that  produced  by  the  molding  sand  com- 
panies, is  sold  as  fire  or  furnace  bottom  sand.  It  is  very  satisfactory  because 
it  contains  small  amounts  of  bonding  material  and  is  highly  refractory.  Below 
is  the  sieve  analysis  of  sand  from  the  Utica  district  sold  as  furnace  bottom 
sand : 


27Thomson,    E.    Mechanical    and    other   properties    of   fused    silica  :    Cement.    Mill    and 
Quarry,   vol.    27,   No.    6,   pp.    34-44,    Sept.    20,   1925. 


118  THE   ST.    PETER   SANDSTONE   OF   ILLINOIS 

Per  cent 

Through     28  mesh  on     35   mesh 9 

Through     35  mesh  on     48  mesh 32 

Through     48   mesh  on     65  mesh : 19 

Through     65   mesh  on   100  mesh 20 

Through   100  mesh  on   150  mesh ; 14 

Through    150   mesh 6 

Glass  Sand 

Quartz  sand  (Si02)  is  an  important  constituent  of  most  glasses  and  con- 
stitutes from  50  to  65  per  cent  of  the  raw  mix.  It  is  known  commercially  as 
glass  or  melting  sand.  There  are  many  different  kinds  of  glasses.  The  follow- 
ing classification  indicates  the  different  types  and  their  general  composition. 

TECHNICAL   CLASSIFICATION   OF   GLASSES28 

The  glasses  of  chief  importance  may  conveniently  be  classified  as  follows : 

1.  Polished  plate  embraces  all  glass  cast  upon  a  smooth  table,  rolled  to 
the  required  thickness  with  a  roller,  annealed,  and  then  ground  and  polished. 

2.  Rough  plate  embraces  all  glass  cast  as  above,  but  not  ground  and 
polished.  The  principal  varieties  are  ribbed  plate,  colored  cathedral,  rough 
plate,  wire  glass  and  heavy  rough  plate  for  skylights. 

3.  Window  glass  embraces  all  glass  blown  in  cylinders,  and  afterwards 
cut,  flattened  out  and  polished  while  hot.  Chiefly  used  for  glazing,  pictures, 
mirrors,  etc. 

4.  Crown  glass  embraces  glass  blown  in  spherical  form  and  flattened  to 
a  disk  shape  by  centrifugal  motion  of  blow  pipe.  A  little  is  made  at  the 
present  time  for  decorative  purposes. 

5.  Green  glass  embraces  all  the  common  kinds  of  glass,  and  is  not  nec- 
essarily green  in  color.  It  is  used  in  the  manufacture  of  bottles,  carboys,  fruit 
jars,  etc. 

6.  Lime  flint  embraces  the  finer  grades  of  bottles  used  for  the  prescrip- 
tion trade,  tumblers,  certain  lines  of  pressed  tableware  and  novelties. 

7.  Lead  flint  embraces  all  the  finest  products  of  glass  making  such  as 
fine  cut  glass,  table  ware,  optical  glass,  artificial  gems,  etc. 

IMPURITIES   IN   GLASS   SAND 

The  most  common  impurities  found  in  glass  sands  are  iron,  clay  mate- 
rials, magnesia,  earthy  and  organic  material.  These  impair  the  transparency, 
brilliancy  or  hardness  of  the  glass.  Iron  colors  the  glass  green,  yellow,  or 
brownish,  depending  on  the  amount  and  chemical  character  of  the  iron  com- 
pounds present.  The  iron  in  glass  sands  may  occur  as  a  thin  film  or  coating 
on  the  grains  of  sand  or  as  iron  minerals  such  as  pyrite,  magnetite,  ilmenite,  or 


2SLinton,   Robert,   Glass  :  Min.   Industry   for   1899,  vol.   VIII,   New  York,   pp.    234-263, 
1900. 


USES  OF  SAND  119 

the  like.  The  magnetic  minerals  may  be  removed  by  passing  the  sand  over  a 
magnetic  separator,  but  the  non-magnetic  types  cannot  be  commercially  re- 
moved and  consequently  a  sand  containing  more  than  the  allowable  amount 
of  these  minerals  must  be  avoided. 

Alumina  in  small  amounts  is  said  to  induce  desirable  properties  in  a 
glass.    It  is  present  in  glass  sand  chiefly  as  clay,  feldspar  or  white  mica. 

Lime,  magnesia,  and  other  alkalies  are  generally  avoided  in  sand  for 
high-grade  glasses  in  order  that  careful  and  certain  control  may  be  kept  on 
the  composition  of  the  raw  materials  entering  a  glass  mix. 

SHAPE  OF   SAND  GRAINS 

Theoretically  an  angular  sand  should  melt  faster  than  a  rounded  sand 
composed  of  grains  of  nearly  the  same  size,  because  the  angular  sand  has  a 
greater  theoretical  permeability  and  exposes  more  surface  to  heat  in  propor- 
tion to  its  volume  than  does  the  rounded  sand.  Practically,  however,  it  has 
been  found  that  the  shape  of  the  sand  grains  is  a  comparatively  unimportant 
factor  in  influencing  the  melting  temperature ;  in  fact  some  glass  manufac- 
turers specify  sand  with  rounded  grains. 

SIZE  OF  SAND  GRAINS 

There  are  many  different  opinions  as  to  what  size  sand  is  most  desirable 
for  glass  making.  A  fine  sand  melts  more  readily  than  a  coarse  sand  but  is 
reported  to  yield  less  glass  per  unit  volume  than  a  coarse  sand.  In  a  mixture 
of  fine  and  coarse  sand  the  fine  material  may  settle  to  the  bottom  of  the  batch 
and  result  in  a  glass  of  uneven  texture.  In  general  a  sand  which  is  a  compro- 
mise between  fine  and  coarse  is  used  for  making  glass  and  the  specifications 
which  follow  indicate  the  general  latitude  in  size  allowable  in  a  glass  sand. 

PROPOSED   TENTATIVE    SPECIFICATIONS   FOR   SILICA    SAND   FOR   GLASS-MAKING29 

The  following  are  the  tentative  specifications  for  glass  sand  prepared  by 
the  Committee  on  Standards  of  the  Glass  Section  of  the  American  Ceramic 
Society  in  cooperation  with  the  Bureau  of  Standards. 

GENERAL 

1.  Character  of  sand. — Sand  as  commonly  used  for  glass-making  pur- 
poses is  a  white,  clean,  dry,  fine-grained  quartz,  washed  practically  free  from 
all  clay-like  material  and  other  impurities.  The  chief  criterion  for  a  good 
glass  sand  is  that  it  should  be  practically  all  silica  and  contain  very  little  iron. 

In  view  of  the  increasing  use  of  alumina  in  a  glass  batch  and  of  the  vary- 
ing amounts  of  iron  allowable  in  green  or  amber  glass,  sand  of  lower  grade 


29Bull.   Amer.   Ceramic   Soc,   vol.    2,   No.    3,    pp.   182-183.   March,    1923. 


120 


THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


may  be  used  by  many  manufacturers.  These  specifications,  therefore,  will 
show  a  variety  of  qualities  and  state  more  or  less  definitely  the  types  of  glass 
they  may  be  used  for.  The  quality  number  is  not  to  be  interpreted  as  neces- 
sarily being  an  index  to  the  value  of  the  product. 


REQUIREMENTS 

2.  Packing. — Cars  in  which  sand  is  to  be  shipped  shall  be  thoroughly 
cleaned  before  loading,  and  lined  with  paper  where  sand  is  sold  for  first, 
second  or  third  quality. 

3.  Impurities. — Sand  shall  not  be  contaminated  with  stripping  dirt  or 
contain  any  crushed  stones  or  pebbles.  These  impurities  are  often  insoluble 
in  the  melting  glass,  producing  stones. 

4.  Screening  and  washing. — All  sand  shall  be  screened,  washed  and 
dried  before  shipment,  except  where  the  natural  condition  of  the  quarries  will 
allow  the  production  by  screening  only  of  fourth,  fifth,  sixth  or  seventh 
quality  sand. 

Table  7. — Percentage  composition  of  sands  of  -various  qualities  based  on  ignited  samples 


Qualities 


First    quality    optical    glass- 


Second    quality    flint    glass    containers, 
t  able  w  a  re    


Third  quality,  flint  glass 

Fourth   quality  sheet   glass   rolled    and 
polished    plate    


Fifth    quality    sheet    glass    rolled    and 
polished    plate    


Sixth    quality    green    glass    containers 
and    window   glass 


Seventh  quality  green  glass 

Eighth  quality  amber  glass  containers 
Ninth  quality  amber 


SiO. 


Al.,0. 


Fe  O. 


Max.     Min.    Max. 


Min. 


Max. 


Min. 


CaO-f-MgO 


Max.      Min 


99.8 

0.1 

98.5 

0.5 

95.0 

4.0 

98.5 

0.5 

95.0 

4.0 

98.0 

0.5 

95.0 

4.0 

98.0 

0.5 

95.0 

4.0 

.02 

.035 
.035 

.06 

.06 


0.3 
0.3 
1.0 
1.0 


0.1 

0.2 

0.5 

0.5 

0.5 

0.5 

0.5 

0.5 

0.5 

1 

5.  Although  sand  may  vary  considerably  in  composition,  depending  on 
the  type  of  glass  to  be  made,  the  composition  of  any  single  quality  specified 
shall  not  vary  from  shipment  to  shipment  more  than  the  amounts  stated  in 
Table  8. 


USES    OF   SAND 

121 

Table  8. — Percentage  tolerances  in  composition  allowed 

(based  on  ignited 

sample) 

Quality 

SiO., 

Alo0, 

Fe.,Oq 

2      3 

Ca04-MgO 

Rmx 

1 

±0.1% 

±0.05% 

+  0.005% 

±0.05 

2 

±0.5 

±0.1 

4-0.005 

±0.05% 

3 

±1.0 

±0.5 

4-0.005 

±0.1 

4 

±0.5 

±0.1 

.+  0.005 

±0.1 

5 

±1.0 

±0.5 

4-0.005 

±0.1 

6 

±1.0 

±0.5 

±0.05 

±0.1 

7 

±1.0 

±0.5 

±0.05 

±0.1 

8 

±1.0 

±0.5 

±0.1 

±0.1 

9 

±1.0 

±0.5 

±0.1 

±0.1 

6.     Sand  shall  be  prepared  so  that  the  size  of  grains  shall  be  rather 
uniform  and  be  within  the  limits  set  in  Table  9. 

Table  9. — Limiting  per  cents  of  various  sizes  of  sand  grains 


Through 
Through 

q 

No 

20  screen _ 

a 

No. 

20  and  remaining  on  a  No.  40 

Through 

a 

No. 

40   and   remaining  on   a  No.   60 

Through 

a 

No. 

60  and  remaining  on  a  No.  100 

screen 

Through 

a 

No. 

100   screen 

100% 

Not    more   than   60%    nor   less   than   40% 

Not   more   than  40%    nor   less   than   30% 

Not   more   than   20%    nor   less   than    10% 
Not  more  than   5% 


ST.  PETER  SAND  AS  A  GLASS  SAND 

The  St.  Peter  sand  has  long  been  known  as  a  very  high-grade  glass  sand. 
The  washed  and  dried  sand  which  is  sold  for  making  glass  is  very  pure,  high 
in  silica  and  low  in  impurities  including  especially  iron.  Repeated  analyses 
give  the  silica  content  as  over  99.97  per  cent.  In  general  the  magnesia  varies 
from  a  trace  to  about  0.01  per  cent,  the  lime  content  from  nothing  to  0.02 
per  cent,  the  iron  oxide  from  nothing  to  about  0.02  per  cent  and  the  alumina 
from  nothing  to  about  0.05  per  cent. 

As  indicative  of  the  requirements  which  the  St.  Peter  sand  meets  the 
following  specifications  from  companies  using  the  sand  are  given : 


122  THE    ST.    PETER    SANDSTONE   OF    ILLINOIS 

Sand  for  making  sheet  glass: 

All  sand  must  pass  20  mesh  and  not  over  2  per  cent  should  pass  150  mesh.       Sand 
from  a  given   source   should   be   uniformly  sized.     As   far   as   practicable,  it  is   desired 
that  a  negligible  amount  of  the  sand  be  finer  than  100  mesh. 
Sand  for  making  plate  glass: 

100  per  cent  must  pass  16  mesh,  98  per  cent  be  retained  on  120  mesh. 

85  per  cent  must  pass  30  mesh,  80  per  cent  be  retained  on  60  mesh. 

The  color  of  the  sand  must  be  white;  the  shape  of  the  grains  is  unessential.  The 
sand  should  meet  the  following  chemical  specifications: 

Per  cent 

Silica minimum    permissible    99.50 

Alumina maximum    permissible    - — 0.15 

Magnesia maximum    permissible    _ 0.10 

Lime maximum    permissible    _ 0.10 

Iron  oxide maximum   permissible   - 0.05 

Sand  for  flint  bottles: 

100  per  cent  must  pass  20  mesh;  34  per  cent  be  retained  on  40  mesh;  90  per  cent 
be  retained  on  60  mesh. 

Color  must  be  white ;  rounded  grains  are  preferred.  The  chemical  analysis  of  the 
sand  should  pass  the  following  specifications: 

Per  cent 

Silica minimum    permissible    _ 99.05 

Alumina maximum    permissible    0.05 

Magnesia maximum    permissible    0.10 

Lime maximum    permissible    0.05 

Iron  oxide maximum    permissible    0.04 

Sand  for  Making  Glazes 

In  the  manufacture  of  such  ceramic  products  as  chinaware,  porcelain, 
pottery,  and  stoneware,  a  glaze  is  applied  to  give  the  ware  an  impervious, 
smooth,  glassy  exterior.  Silica  is  an  essential  constituent  of  these  glazes  which 
are  really  a  glass. 

In  general  a  sand  possessing  the  properties  of  a  high-grade  glass  sand  is 
used  for  making  glazes.  Such  sands  commonly  contain  less  than  0.02  or  0.03 
per  cent  of  iron  oxide,  and  very  minor  amounts  of  alumina  and  other  oxides. 
The  sand  may  be  either  purchased  as  the  natural  grain  and  ground  by  the 
consumer  or  obtained  already  pulverized.  Commonly  a  product  fine  enough 
to  pass  through  120  to  140  mesh  is  used. 

Since  the  St.  Peter  sandstone  is  a  high-grade  glass  sand,  it  is  a  very 
suitable  material  for  use  in  making  glazes.  The  sand  may  be  obtained  as 
screened  washed  sand  or  as  ground  silica.  It  is  most  commonly  sold  by  the 
Illinois  plants  in  the  ground  form. 

Sand  for  Golf  Tees,  Traps,  Hazzards,  and  Greens 

A  clean,  white,  medium-grained  sand  is  used  for  golf  tees.  Sand  is  also 
used  for  constructing  various  hazzards  and  traps,  and  sand  greens  in  golf 
courses.    A  moderately  clean  sand  is  commonly  specified  for  this  purpose. 


USES  OF  SAND  123 

Grinding  and  Polishing  Sand 

Sand  is  commonly  employed  as  an  abrasive  for  the  rough  grinding  of 
stone.  The  grinding  is  done  on  a  rotating  circular  table  known  as  the  grind- 
ing bed,  on  to  which  the  sand  is  fed  with  water.  Sand  is  also  used  for  smooth- 
ing and  grinding  sanitary  ware,  terra  cotta,  and  other  ceramic  products.  The 
process  is  carried  out  on  a  horizontal  iron  lap. 

Another  use  for  abrasive  sand  is  in  the  grinding  of  a  smooth  surface  on 
crude,  rolled  plate  glass  before  it  is  given  its  final  grinding  and  polishing.  The 
sheets  of  glass  as  they  emerge  from  the  annealing  oven  have  an  undulating, 
opaque  surface.  They  are  set  in  a  bed  of  Plaster  of  Paris  and  fastened  with 
pegs  to  the  grinding  table  which  consists  of  a  large  rotatable  iron  platform. 
The  table  is  then  set  in  motion  and  sand  and  water  fed  upon  the  surface  of 
the  glass  plate.  The  grinding  is  done  by  iron  slabs  or  iron  shod  wood  boxes 
which  rest  upon  the  glass.  The  slabs  have  a  revolving  motion  of  their  own 
around  a  vertical  axis. 

A  high  silica  sand,  with  tough  grains,  which  is  free  from  clay  and  other 
foreign  material  is  desired  for  grinding  and  polishing.  It  is  essential  that  the 
sand  be  well  graded  to  remove  large  grains  and  debris  which  might  clog  the 
sand-circulating  system.  Large  grains  are  also  to  be  avoided  because  they 
produce  deep  scratches  in  the  glass  which  may  be  difficult  to  remove  in  the 
final  grinding  and  polishing.  The  shape  of  the  grains  is  of  minor  importance 
as  angular  grains  become  rounded  and  rounded  grains  break  to  yield  angular 
fragments.  A  large  Pennsylvania  plate  glass  company  specifies  rounded  sand 
of  which  100  per  cent  will  pass  16  mesh,  98  per  cent  be  retained  on  120  mesh 
and  80  per  cent  on  60  mesh.  A  Michigan  plate  glass  company  specifies  round- 
ed sand,  light  gray  or  white  in  color,  of  which  100  per  cent  must  pass  20  mesh, 
40  per  cent  be  retained  on  40  mesh  and  88  per  cent  on  60  mesh. 

The  St.  Peter  sandstone  is  very  suitable  for  grinding  and  polishing  since 
it  is  inherently  a  high  silica  sand  with  tough  grains.  The  sand  washed  and 
sized  by  the  plants  at  Ottawa  is  widely  used  for  this  purpose. 

Sand  for  Grinding  Wheels 

Sand  is  used  to  some  extent  as  the  abrasive  constituent  of  srrindmg 
wheels.  These  are  made  by  mixing  sand  with  clay,  rubber,  shellac  or  some 
other  bonding  substance.  In  general  angular  sand  is  preferred  because  the 
bonding  matrix  of  the  wheel  holds  the  angular  particles  more  firmly  than  the 
round  ones,  thus  increasing  the  period  of  use  of  the  wheel.  An  angular  sand 
is  also  said  to  give  a  more  rapidly  cutting  wheel. 

Horticultural  Sands 

In  propogating  cuttings  of  plants  and  shrubs,  horticulturists  commonly 
employ  a  manured  sand  for  the  early  growth  of  the  cuttings.   Another  type  of 


124  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

horticultural  sand  known  as  "potting  sand"  is  mixed  with  about  an  equal 
amount  of  good  loam  and  is  used  for  raising  plants  in  greenhouses  and  under 
glass.  Sand  is  also  used  as  an  essentially  sterile  medium  in  which  to  grow 
plants  in  experimenting  on  the  effect  of  different  substances  on  growth,  color, 
and  characteristics.  Another  type  of  sand,  known  as  "lawn  sand"  is  used  for 
improving  the  color  and  growth  of  lawns. 

It  is  very  important  that  sand  for  horticultural  purposes  be  clean,  well 
sized,  and  free  from  iron,  clay  and  other  impurities  particularly  those  which 
might  effect  a  bacterial  contamination  of  the  plant-growing  medium.  There 
are  no  definitely  specified  sizes  for  sand  for  horticultural  purposes,  but  com- 
monly a  medium  to  coarse  sand  is  used.  The  angularity  or  roundness  of  grain 
is  generally  of  minor  importance.  A  small  sample  of  the  St.  Peter  sand  used 
for  horticultural  purposes  by  the  Agricultural  Department  of  the  University 
of  Illinois,  screened  as  follows :  35  per  cent  retained  on  40  mesh,  38  per  cent 
on  60  mesh,  18  per  cent  on  100  mesh  and  9  per  cent  through  100  mesh. 

Screened  St.  Peter  sand  and  especially  that  which  has  been  washed,  is  a 
very  satisfactory  horticultural  sand  because  of  its  general  cleanness. 

Hour-glass  sand 

Small  amounts  of  fine,  clean,  well-graded  sand  are  used  in  hour  glasses. 
Sand  consisting  of  rounded  grains  between  80  and  100  mesh  is  commonly 
specified  for  this  purpose. 

Sand  for  Use  on  Icy  Streets  and  Walks 

An  increasing  amount  of  sand  is  being  used  for  sanding  icy  walks  and 
pavements,  particularly  in  hilly  cities,  in  order  to  prevent  pedestrians  and 
vehicles  from  slipping.  The  sand  is  also  valuable  because  it  absorbs  more  of 
the  sun's  heat  than  ice  does  and,  by  transferring  it  to  the  ice  beneath  it,  causes 
melting  at  a  lower  temperature  and  more  rapidly  than  normal. 

A  moderately  coarse  to  coarse  sand  is  preferable  for  this  purpose.  It 
should  be  free  from  clay  or  silt,  since  these  decrease  the  efficiency  of  a  sand 
in  melting  ice  and  result  in  a  disagreeable  mud  after  the  ice  has  melted. 

Loam  (See  molding  sand,  pp.  125-130) 

Sand  for  Matches 

Ground  sand  (silica)  is  used  as  one  of  the  ingredients  of  match  heads. 
Medium  sized  sand  is  used  to  form  a  rough  surface  on  the  side  of  match 
boxes  for  striking  the  matches.  Fine  sand  of  about  100-mesh  size  is  also  used 
lo  coat  the  sides  of  the  pocket  size  boxes.  » 


USES   OF   SAND  125 

Sand  as  a  Moisture  Pad30 
In  order  to  prevent  concrete  sidewalks  and  other  like  construction  from 
drying  too  rapidly  a  clean  sand  is  sometimes  spread  over  the  surface  in  a 
layer  sufficiently  thick  so  that  when  the  sand  is  wetted  periodically  it  will 
contain  enough  water  to  keep  the  concrete  moist  until  it  has  set  thoroughly. 

Silica  or  Sand  Mold  Wash   (See  facing  sand,  p.  113) 

Molding  Sand 
Molding  sands  may  be  divided  into  two  general  groups,  namely  common 
molding  sand,  sometimes  called  foundry  sand,  and  steel  molding  sand  some- 
times designated  as  steel  sand.  The  former  is  used  in  making  castings  re- 
quiring a  sand  which  will  withstand  a  moderately  high  temperature  and  which 
is  moderately  refractory.  Common  molding  sands  are  also  expected,  in  gen- 
eral, to  have  a  relatively  high  per  cent  of  natural  bond.  Steel  molding  sand 
must  be  highly  refractory  because  of  the  high  temperature  of  the  molten  steel 
cast  in  it,  and  in  general  is  not  required  to  have  a  high  per  cent  of  natural 
bond.  In  fact  some  steel  foundries  buy  washed  sand,  preferring  to  add  a 
predetermined  amount  of  artificial  bond  such  as  molasses  or  flour.  In  this  way 
a  more  uniformly  bonded  sand  is  secured  than  when  the  natural  product  is 
used  with  a  bond  varying  in  character  and  amount.  Special  names  are  given 
to  molding  sands  used  in  different  parts  of  the  operations  of  molding.  The 
more  important  of  these  are  as  follows : 

Core  sand — highly  refractory  sand  used  for  making  the  cores  for  molds. 
Parting  sand — a  fine  sand  consisting  preferably  of  rounded  grains  used 

for  dusting  the  meeting  faces  of  molds. 
Facing  sand — a  sand  which  is  generally  fine,  used  to  coat  the  inside  of 

molds  in  order  to  give  the  casting  a  smooth  surface. 
Green  sand — raw  molding  sand  used  in  a  moist  condition. 
Dry  sand — molding  sand  which  while  damp  is  shaped  into  molds  and 

then  allowed  to  dry  before  metal  is  poured  into  it. 
Loam — a  mixture  of  clay  and  sand  for  molding  large  castings. 
Backing  or  floor  sand — this  type  of  sand  makes  up  the  bulk  of  the  mold. 
It  gives  the  mold  its  strength  and  offers  escape  to  the  gases  formed  at 
the  contact  of  the  mold  and  the  molten  metal. 

THE  PROPERTIES  AND  TESTING  OF  MOLDING  SANDS31 

In  view  of  the  great  number  of  different  types  of  molding  operations  in 
which  sand  is  used  it  is  obvious  that  the  physical  properties  of  the  sands  best 


30Condra,  G.  EI.,  The  sand  and  gravel  resources  and  industries  of  Nebraska:  Ne- 
braska  Geol.    Survey,   vol.    3,    pt.    1,    p.    169,    1908. 

3iA  great  deal  of  work  has  been  and  is  being  done  on  the  physical  properties  of 
molding  sands  by  the  American  Foundrymen's  Association.  For  details  on  the  testing 
of  molding  sand  the  reader  is  referred  to  the  bulletin  of  that  Association  for  June  1, 
1924,  or  to  Illinois  State  Geol.  Survey  Bull.  50  in  which  the  specifications  for  testing  are 
reprinted. 


126  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

fitted  for  the  various  types  of  work  will  also  be  varied.  Following  is  a  brief 
statement  of  the  different  physical  properties  of  molding  sands  and  a  few 
specifications  showing  the  character  of  the  St.  Peter  sand  used  in  molding. 

1.  Bond  strength.  The  bond  strength  or  cohesiveness  of  a  sand  is  its 
ability  to  stick  together  and  upon  this  property  depends  in  part  the  character 
of  the  mold  a  sand  will  make.  Cohesiveness  depends  principally  on  the 
amount,  character,  and  distribution  of  the  bonding  material,  and  the  shape, 
size  and  character  of  the  surface  of  the  sand  grains  bonded.  Clay  and  limonite 
are  the  bonds  most  commonly  encountered  in  natural  bonded  molding  sands. 
It  is  sometimes  desirable  to  add  an  artificial  bond  to  a  silica  sand  which  is 
highly  refractory  but  low  in  bond.  Such  artificial  bonds  as  flour,  molasses  or 
other  sugary  syrup,  gluten,  oil  of  various  sorts  or  fire  clay  are  used.  In 
general  an  angular  sand  is  said  to  have  greater  bonding  power  than  a  rounded 
sand  as  a  result  of  the  strength  gained  through  the  interlocking  of  the  grains. 
The  character  of  the  surface  of  the  sand  grains  composing  the  molding  sand 
is  also  of  importance  inasmuch  as  frosted  grains  give  a  much  better  oppor- 
tunity for  the  adhesion  of  the  bonding  material  than  do  smooth  surfaced 
grains.  A  fine  sand  has  a  greater  bond  strength  than  a  coarse  one  because  the 
amount  of  surface  tension  of  the  water  film  between  the  grains  is  greater,  and 
the  surface  for  adhesion  of  the  bond  is  proportionately  larger.  An  even  dis- 
tribution of  bonding  material  is  also  essential  to  maximum  cohesiveness. 

2.  Permeability.  Permeability  is  that  property  of  a  molding  sand  which 
permits  the  venting  of  gases  evolved  at  the  surface  of  the  mold  in  contact  with 
the  molten  metal.  Technically,  permeability  of  the  crude  sands  is  measured 
when  these  sands  are  tempered  with  such  an  amount  of  water  as  to  give  the 
maximum  permeability  (optimum  water  content).  Base  permeability  is  the 
measure  of  the  permeability  of  the  grains  of  a  sand  with  the  bond  removed. 
It  is  very  important  in  general  that  a  sand  should  have  a  permeability  suffi- 
cient to  allow  the  ready  escape  of  gases,  else  serious  imperfections  may  result 
on  the  surface  of  the  casting.  The  size  of  the  sand  determines  in  a  large 
measure  its  permeability.  A  fine  sand  is  less  permeable  than  a  coarse  one; 
also  a  sand  consisting  of  sand  grains  of  various  sizes  is  not  highly  permeable 
because  the  difference  in  size  permits  a  tight  packing  of  the  grains.  A  sand 
composed  of  rounded  sand  grains  of  a  given  size  has  greater  permeability 
than  an  angular  sand  of  the  same  size,  principally  because  the  pore  space  in 
rounded  sands  is  more  continuous  than  in  angular  sands.  The  amount  of 
bonding  material  and  water  present  also  influences  permeability.  Both  clog 
the  pores  of  the  sand  and  the  maximum  working  permeability  is  therefore 
commonly  obtained  when  the  amounts  of  water  and  bond  are  kept  at  a  mini- 
mum. The  temperature  and  type  of  metal  to  be  cast  is  a  fourth  factor  influ- 
encing permeability.  Some  metals  close  the  pores  in  the  surface  of  a  mold 
and  therefore  necessitate  the  use  of  highly  permeable  sands. 


USES   OF   SAND  127 

3.  Texture.  The  texture  of  sands  is  commonly  expressed  as  the  per 
cents  by  weight  retained  on  a  given  set  of  sieves.  Texture  is  a  very  important 
property  of  sand,  and  bears  an  important  relation  to  bonding  strength  and 
permeability  as  mentioned  under  those  topics. 

4.  Durability.  The  durability  of  a  sand  is  its  ability  to  withstand  re- 
peated using  without  marked  deterioration.  This  property  seems  to  be  depend- 
ent principally  in  the  amount  and  character  of  the  bond  present.  Detailed 
data  on  the  rate  of  deterioration  of  the  various  types  of  sand  are  not 
available. 

5.  Refractoriness.  Refractoriness  is  that  property  of  a  sand  which 
enables  it  to  withstand  high  temperatures  without  fusing.  The  refractoriness 
which  a  molding  sand  should  possess  depends  on  the  sort  of  metal  to  be  cast. 
The  sand  should,  of  course,  have  a  higher  fusion  point  than  the  temperature 
of  the  molten  metal  cast  in  it.  Searle32  gives  the  following  casting  tempera- 
tures for  different  metals : 

Sand  for  casting  Maximum  temperature  attained 

Brass    1350°C 2462°F. 

Iron    1510°C 2750°F. 

Steel 1580°-1650°C 2876°-3002°F. 

The  chief  factor  influencing  the  refractoriness  of  molding  sands  is  the  im- 
purities present,  either  in  the  bond  or  as  grains  which  may  act  as  fluxes  and 
lower  the  fusion  point  of  the  quartz.  Pure  quartz  will  fuse  between  1700° 
(3092°F.)  and  1800°C.  (3272°F.)  Because  of  the  smaller  surface  area  pre- 
sented in  proportion  to  their  volume,  large  grains  of  sand  take  longer  to  heat 
than  small  ones,  and,  other  things  being  equal,  a  coarse  sand  will  be  more 
refractory  than  a  fine  one.  For  similar  reasons,  a  rounded  sand  is  more 
refractory  than  an  angular  one  under  identical  conditions. 

6.  Color.  The  color  of  a  molding  sand  is  in  general  unimportant  except 
as  it  indicates  the  presence  of  some  colored  substance  and  its  approximate 
amount.  Thus  a  yellow  or  red  sand  is  probably  relatively  high  in  iron  oxide 
content,  and  a  white  sand  probably  contains  a  much  smaller  amount  of  the 
same  sort  of  material. 

7.  Chemical  composition.  The  chemical  composition  of  a  sand  is  im- 
portant, for  from  it  may  be  determined  the  amount  and  chemical  character  of 
material  other  than  quartz  which  is  present.  In  this  way  the  amount  and 
character  of  fluxing  or  gas-producing  impurities  are  determinable. 

8.  Mineralogical  composition.  Data  on  the  character  and  amount  of 
the  different  mineral  constituents  of  a  sand  may  be  obtained  from  a  miner- 
alogical examination.  This  study  is  of  great  value  as  preliminary  or  supple- 
mentary to  a  chemical  analysis. 

9.  Shape  of  grains.  The  shape  of  the.  grains  composing  a  sand  is  an 
important  factor  influencing  the  porosity  of  the  sand  and  its  refractoriness. 


sssearle,  A.   B.,   Sands  and  crushed  rocks,   vol.    2,  p.   81,   London,   1923. 


128  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

It  is  commonly  stated  that  angular  sands  have  a  higher  bonding  strength  than 
rounded  sands.  For  sands  using  plastic  bonds,  it  is  probably  true  in  general 
that  the  character  of  the  surface  of  the  grains  is  as  important  as  the  shape  of 
the  grains  as  far  as  the  bonding  strength  is  concerned ;  that  is,  a  sand  whose 
grains  are  roughened  and  to  which  the  bond  adheres  readily  is  likely  to  have  a 
higher  bonding  strength  than  a  sand  composed  of  smooth  grains.  The  fact 
that  rounded  grains  are  more  likely  to  have  a  roughened  surface  than  angular 
grains  has  been  previously  mentioned  and  its  bearing  here  is  obvious. 

SPECIFICATIONS    FOR    COMMON    MOLDING    SAND 

It  is  impossible  to  lay  down  any  detailed  specifications  for  common 
molding  sands  because  of  the  number  and  complexity  of  the  combinations  of 
properties  which  may  be  united  in  different  ways  to  give  equally  satisfac- 
tory sands  for  the  same  or  different  types  of  molding.  In  general,  how- 
ever, it  would  seem  that  common  molding  sand  should  meet  the  following 
requirements : 

1.  The  sand  should  be  free  from  large  lumps  or  foreign  material. 

2.  The  sand  should  be  free  from  fluxing  impurities  as  constituents  of  either  the 
sand  or  the  bond,  which  are  active  below  the  maximum  temperature  to  which  the  sand 
is  to  be  submitted.     Because  of  its   refractoriness,   a  high  content  of  quartz  is  desirable. 

3.  The  sand  should  consist  of  grains  with  such  a  surface  and  of  such  size  or  sizes 
and  shape  as  to  give  the  necessary  permeability  and  cohesiveness  to  the  sand  with  the 
bond  used.  Further,  it  is  desirable,  if  possible,  to  arrange  the  preceding  combination 
so  as  to  give  the  casting  the  finish  desired  without  the  use  of  facing  sand. 

4.  The  bond  should  be  as  lasting  and  durable  as  possible,  and  present  in  sufficient 
quantity  to  obviate  the  addition  of  a  further  amount  of  bond  to  the  crude  sand. 

SPECIFICATIONS   FOR   STEEL    MOLDING   SAND   AND   CORE   SAND 

The  chief  requirements  for  these  types  of  sand  are  that  they  be  highly 
refractory  and  consist  of  grains  of  such  sizes  and-  shapes  as  to  give  the 
requisite  permeability  with  the  bond  used.  Inasmuch  as  core  sand  is  often 
entirely  enclosed  in  molten  metal  it  must  be  even  more  refractory  than  steel 
sand.  For  most  purposes  a  grain  with  a  roughened  surface  is  desirable  since 
this  property  gives  the  bond  a  better  hold  on  the  grain.  A  rounded  sand  is 
usually  preferred.  The  amount  of  bond  present  in  the  crude  sand  is  not 
always  essential  inasmuch  as  artificial  bonds  are  very  commonly  used  with 
steel  molding  sands.  The  sand,  particularly  the  core  sand  should,  of  course, 
be  very  low  in  impurities,  especially  fluxes,  and  should  be  free  from  hard 
lumps  and  foreign  substances. 

THE  ST.   PETER  SAND  AS  A    MOLDING   SAND 

The  St.  Peter  sand  sold  for  molding  purposes  is  used  primarily  as  a  steel 
molding  and  core  sand.  It  is  not  generally  a  natural  bonded  sand  and  is 
therefore,  not  commonly  used  as  molding  sand  where  natural  bonded  sands 


USES  OF   SAND 


129 


are  readily  available  and  highly  refractory  sands  are  not  needed.  As  a  steel 
molding  and  core  sand  the  St.  Peter  is  widely  used  in  the  middle  west.  The 
following  specifications  give  an  idea  of  the  character  of  the  sand  in  commer- 
cial use  for  different  types  of  castings: 

Steel  molding  and  core  sand  for  casting  car  wheels  and  structural  steel  , 
Representative    sieve    analysis:  Per  cent 

Sand  passing  through  100  mesh  sieve .., , — _.....     2.96 

Sand  passing  through     80  mesh  sieve , .,....,..,... „,. —     2.75 

Sand  passing  through     60  mesh  sieve — ._     8.41 

Sand  passing  through    40  mesh  sieve ~ 42.87 

Sand  passing  through     20  mesh  sieve . _.  42.6 

Sand  retained  on  20  mesh  sieve — 3 

Fineness  number — 35.9 

Color — not  essential;   usually  light  yellow  tinge. 

Shape    of    grains — round    grains    preferred,    to    allow    for    safe    void    between    sand 

after  it  is  rammed   and  to  insure  porosity  and  permeability. 

Chemical  analysis — silica  content  over  96  per  cent  preferred.     Lime1  should  be  kept 

at  minimum. 

Sand  for   molding   bars,  shapes   and  light  rails 

Sieve  analysis:  Per  cent 

Sand  passing  100  mesh  sieve 3.2 

Sand  passing     80  mesh  sieve ,. 1.2 

Sand  passing     60  mesh  sieve ~.     6.1 

Sand  passing     40  mesh  sieve 39.3 

Sand  passing     20  mesh  sieve 50.2 

Fineness  number — 33.2 
Color — unessential. 
Shape  of  grain — rounded. 

Chemical  analysis:  Per  cent 

Silica minimum  permissible     98.0 

Alumina    maximum  permissible       1.0 

Magnesia  maximum  permissible         .1 

Lime maximum  permissible         .5 

Iron    oxide maximum  permissible         .5 

Sand  for  car  couplers 
Sieve  analysis: 

10  per  cent  must  be  retained   on  20  mesh  sieve 

30  per  cent  must  be  retained   on  40  mesh  sieve 

40  per  cent  must  be   retained   on  60  mesh   sieve 

80  per  cent  must  be  retained   on   80  mesh  sieve 

Color — prefer  sands  lacking  high  color. 

Shape  of  grains — rounded. 

Chemical   analysis:  Per  cent 

Silica    minimum   permissible     97.0 

Soda,,    potash,    and   lime maximum  permissible       0.4 

Total — alumina,  magnesia,  lime,  soda,  potash,  and  iron 

oxide maximum  permissible       2.0 

The  following  references  on  steel  molding  sand  contain  additional  data : 

Cole,  L.  H.,  Silica  in  Canada,  Part  I:  Canada  Dept.  Mines,  Mines  Branch  No.  555, 
p.  26,  1923. 

Condra,  G.  E.,  The  sand  and  gravel  resources  and  industries  of  Nebraska:  Ne- 
braska Geol.  Survey,  vol.  3,  pt.  1,  pp.  190-191,  1911. 

Dake,  C.  L.,  The  sand  and  gravel  resources  of  Missouri:  Missouri  Bur.  Geol.  and 
Mines,  vol.  15,  2d  ser.,  pp.  73-75,  1918. 

Littlefield,  M.  S.,  Natural-bonded  molding  sand  resources  of  Illinois;  Illinois  State 
Geol.  Survey  Bull.  50,  1925. 


130  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

Ries,  H.,  and  Gallup,  F.  L.,  Molding  sands  of  Wisconsin:  Wisconsin  Geol.  and 
Nat.  Hist.  Survey,  vol.  15,  pp.  198-259,  1906. 

Ries,  H.,  and  Rosen,  J.  A.,  Foundry  sands  of  Michigan:  Michigan  Geol.  Survey, 
Ninth  Ann.  Rept.,  pp.  41-85,  1908. 

Ries,  H.,  and  Nevin,  C.  M.,  The  cohesiveness  test  for  foundry  sands:  Amer.  Foun- 
drymen's  Assoc.  Reprint  No.  374. 

Ries,  H.,  The  testing  of  molding  sands:  Sibley  Jour,  of  Eng.,  vol.  38,  No.  6, 
June,  1924. 

Searle,  A.  B.,  Sands  and  crushed  rocks,  vol.  2,  pp.  75-129,  London,  1923. 

Teas,  L.  P.,  Preliminary  report  on  the  sand  and  gravel  deposits  of  Georgia:  Geol. 
Survey  of  Georgia  Bull.   37^  pp.   68-72,   1921. 

Mortar  Sand 

Sand  is  an  important  constituent  in  mortars.  The  amount  of  sand  used 
and  the  specifications  for  it  vary  somewhat  according  to  the  type  of  mortar 
and  the  use  for  which  it  is  intended.  The  following  specifications,  however, 
apply  in  general : 

1.  General  physical  properties — the  sand  shall  consist  of  clean,  uncoated 
grains,  and  be  free  from  organic  material,  clay,  silt,  mica,  and  shale  frag- 
ments.    Colored  sands  should  generally  be  avoided. 

2.  Shape  of  grains — it  is  commonly  specified  that  mortar  sand  should 
be  composed  of  angular  grains ;  however,  inasmuch  as  angular  sand  grains  do 
not  commonly  have  a  roughened  surface  it  is  probable  that  a  rounded  grain 
with  a  roughened  surface  could  be  used  with  as  much  advantage  as  a  smooth- 
surfaced,  angular  one. 

3.  Size  of  grain — the  size  of  the  sand  used  for  mortars  depends  largely 
on  the  purpose  for  which  the  mortar  is  intended.  The  sand  should  be  well 
graded  and  in  general  a  fairly  coarse  sand  is  used  except  where  the  mortar  is 
to  be  spread  very  thin ;  then  a  finer  sand  is  employed.  Sand  used  for  most 
construction  work  is  commonly  finer  than  10  mesh,  and  90  per  cent  of  it 
coarser  than  100  mesh. 

4.  Chemical  composition — mortar  sands  should  be  free  from  soluble 
salts  inasmuch  as  these  travel  to  the  surface  of  the  mortar  as  it  dries  and  cause 
an  unsightly  scum.  Some  of  the  efflorescence  seen  on  brick  walls  has  been 
caused  by  the  soluble  salts  which  were  present  in  the  sand  used  in  the  mortar. 
The  salts  penetrate  the  brick  and  later  come  to  the  surface. 

The  St.  Peter  sand  is  a  good  mortar  sand  because  it  is  clean  and  free 
from  soluble  salts,  consists  of  grains  with  a  roughened  surface,  and  is  pro- 
duced in  well-graded  sizes. 

Sand  for  Use  in  Paint  Manufacture 

Very  finely  ground  sand,  ,known  commercially  as  air  or  water  floated 
silica,  or  bolted  silica,  is  used  as  a  pigment  in  certain  paints,  some  of  which 
contain  as  much  as  30  per  cent  of  this  material.  The  principal  requirements 
of  silica  for  this  purpose  are  that  it  be  finely  ground  and  white.    An  angular, 


USES    OF   SAND  131 

sharp-grained  silica  is  preferred  because  it  gives  the  paint  a  "tooth".  Crushed 
glassy  quartz  is  said  to  give  a  more  angular  grain  in  general  than  the  amor- 
phous varieties  of  silica.3"  Ground  silica  is  also  used  as  a  filler  in  some  paints ; 
rounded  grains  are  said  to  give  the  paint  smoother  working  qualities. 

The  St.  Peter  sand  grains  are  glassy  quartz  and  the  ground  silica  pro- 
duced from  the  sand  is  very  satisfactory  for  use  in  paints. 

Parting  Sand  (See  molding  sand,  pp.  125-130) 

Placing  Sand  (See  saggar  sand,  p.  136) 

Sand  for  Plasters 

Sand  is  an  important  ingredient  in  all  kinds  of  plasters  except  certain 
types,  such  as  plaster  of  Paris,  which  are  used  without  the  addition  of  any 
extraneous  material.     Plasters  may  be  classified  as  follows : 

(A)  Wall   plasters 

(1)  Gypsum   or   plaster   of  Paris  plasters 

(2)  Lime  plasters    (either  calcium  or  magnesium  limes) 

(3)  Portland  cement  plasters    (more  exactly  mortars) 

(B)  Floor  plasters   and   hard  finish  plasters 

The  amount  of  sand  used  in  the  various  plasters  mentioned  above  de- 
pends largely  on  the  character  of  finish  and  strength  desired  when  the  plaster 
has  set.  The  following  specifications  will  serve  to  indicate  the  general  require- 
ments which  sand  for  plaster  must  meet : 

Lime  plaster  :34  "The  sand  should  preferably  be  composed  of  sharp,  angu- 
lar particles,  clean  and  free  from  vegetable  matter,  loam,  large  stones,  dust 
and  silt.  .  .  .  Tests  show  that  a  well-graded  coarse  sand  makes  the  best 
mortar." 

Gypsum  plaster  :35  (a)  Sand  used  for  a  gypsum  plaster  shall  be  free  from 
alkaline,  organic  and  other  deleterious  substances.  All  sand  must  be  dry, 
clean,  and  sharp. 

(b)  It  shall  be  graded  from  fine  to  coarse,  and  when  dry  not  more  than 
10  per  cent  by  weight  shall  be  retained  on  a  No.  8  sieve ;  not  less  than  80  per 
cent  by  weight  shall  be  retained  on  a  No.  50  sieve,  and  not  more  than  6  per 
cent  by  weight  shall  pass  a  No.  100  sieve.  These  sieves  shall  meet  the  speci- 
fications given  in  the  Bureau  of  Standards'  Standard  Screen  Scale.30 

Cement  plasters:37 

Sand  shall  be  dry,  clean,  and  sharp,  and  shall  conform  as  nearly  as 
possible  to  the  following: 


33Cole.  L.  IT.,  Silica  in  Canada,  Part  I  :  Canada  Dept.  Mines,  Mines  Branch  No.  555, 
p.    32.    1923. 

34Lime — The  binder  in  your  wall:  Nat.  Lime  Assoc.  1924. 

35General  instructions  and  specifications  for  gypsum  plasters,  The  Gypsum  Indus- 
tries,   844   Rush    St.,   Chicago,    111. 

scSee  American  Society  for  Testing  Materials  Specifications  for  Gypsum  Plastering 
Sand,    Serial   Designation   C35. 

37Sweets  Architectural   Catalogue,    20th    ed.,   p.    363,   New  York,    1925-1926. 


132  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

(a)  It  shall   be   free   from   silt   and   from   alkaline,   organic,   and   other   deleterious 

substances. 

(b)  Not  more  than  10  per  cent  shall  be  retained  on  a  No.  8  sieve. 
Not  less  than  80  per  cent  shall  be  retained  on  a  No.   50  sieve. 
Not  more  than  6  per  cent  shall  pass  a  No.  100  sieve. 

Sieves  shall  meet  the  specifications  of  the  U.  S.  Bureau  of  Standards'  Standard 
Screen    Scale. 

Because  the  St.  Peter  sand  is  produced  well  graded,  dry,  and  free  from 
impurities  it  makes  a  very  suitable  plaster  sand.  It  is  not  an  angular  sand, 
however.  Wiley,38  discussing  the  angularity  of  sands  with  reference  to  the 
strength  of  the  mortar  they  make,  says :  "The  usual  requirement  of  specifi- 
cations that  sands  for  mortar  and  concrete  shall  be  sharp  is  not  only  useless 
but  may  even  be  detrimental  and  should  therefore  be  omitted.  Further,  since 
the  condition  of  the  grain  surfaces  does  materially  affect  the  strength  of  the 
mortar  (the  rougher  surfaced  grains  giving  the  stronger  mortar)  the  specifi- 
cations should  fully  cover  this  point."  The  frosted  surfaces  of  the  grains  of 
the  St.  Peter  sand  are  therefore  probably  in  part  responsible  for  the  satisfac- 
tory mortar  which  this  sand  produces  and  its  wide  use  for  plastering.  Three 
companies  using  Illinois  St.  Peter  sand  for  composition  stucco  and  flooring 
are  using  sand  which  meets  the  following  specifications : 

55  per  cent  passes  20  mesh  sieve  and  is  retained  on  35  mesh  sieve. 

38  per  cent  passes  35  mesh  sieve  and  is  retained  on  65  mesh  sieve. 

7  per  cent  passes  65  mesh  sieve  and  is  retained  on  115  mesh  sieve.  The  sand  must 
be  white. 

100  per  cent  passes  20  mesh  sieve  and  100  per  cent  is  retained  on  120  mesh  sieve. 
The  sand  must  be  white ;   rounded  grains  are  preferred. 

100  per  cent  passes  10  mesh  sieve   and  95  per  cent  is  retained  on  100  mesh  sieve. 

65  per  cent  is  retained  on  48  mesh  sieve. 

80  per  cent  is  retained  on  80  mesh  sieve. 

The  color  must  be  white  or  light  cream;  rounded  grains  are  preferred. 

One  company  using  Illinois  St.  Peter  sand  in  the  manufacture  of  finish 
coat  gypsum  plasters  specify  the  following: 

(a)  Finish  coat  white  sand  shall  be  free  from  salts,  alkali,  organic  or  other  dele- 
terious  substances. 

(b)  It  may  be  either  a  native  sand  or  a  screened  product  and  when  dry  not  more 
than  5  per  cent  by  weight  shall  be  retained  on  the  20-mesh  sieve;  not  less  than  70  per 
cent  shall  be  retained  on  the  50-mesh  sieve ;  and  not  more  than  10  per  cent  shall  pass 
through  the  100-mesh  sieve.  The  sieves  used  shall  meet  the  specifications  of  the  Standard 
Sieve  Series  as  described  by  the  U.  S.  Bureau  of  Standards. 

(c)  The  color  shall  be  as  nearly  white  as  possible,  but  shall  not  be  darker  than 
the  Standard  Ottawa  Silica  Testing  Sand. 

Sand  for  Plugging  Oil  Wells 

Most  oil  wells  which  are  unsuccessful  in  obtaining  oil  are  plugged  or 
refilled.  Sand  is  used  to  refill  some  of  these  wells.  Any  available  sand  is 
suitable. 


.".KWiley,    C.    C,    The    mortar-making    qualities    of    Illinois    sands:    Univ.    of    Illinois 
Eng.   Exp.   Station  Bull.   70,   p.   28,   1913. 


USES   OF   SAND  133 

Polishing  Sand  (See  grinding  sand,  p.  123) 
Sand  for  Use  in  the  Manufacture  of  Pottery 

Such  products  as  chemical  and  electrical  porcelain,  art  pottery,  table 
ware,  sanitary  ware  and  floor  and  wall  tiles  are  included  under  the  name  of 
pottery,  and  about  35  per  cent  of  finely  ground  quartz  is  used  in  making  up 
the  body  of  the  ware.  The  quartz  reduces  the  shrinkage  of  the  body  during 
drying  and  gives  it  rigidity  during  firing.  Sometimes  quartz  is  used  to  reduce 
the  plasticity  of  the  clay. 

A  sand  which  is  to  be  ground  for  use  in  the  pottery  industry  should  not 
contain  over  0.32  per  cent  iron  and  should  burn  a  dead  white.  According  to 
Cole39  the  material  should  be  ground  so  that  all  of  it  will  pass  120  mesh  and 
90  per  cent  150  mesh.  The  tentative  specifications  of  the  American  Ceramic 
Society  for  silica  for  whiteware  follow : 

Proposed  Tentative  Specifications  Covering  the  Purchase  of  Pulverized  Flint40 
to  be  used  in  the  manufacture  of  whiteware 

1.  Sample.  In  sampling  car-load  lots,  equal  amounts  should  be  taken  from  at 
least  five  different  points  in  the  car,  no  two  samples  being  taken  within  five  feet  of 
each  other.  In  sampling  from  a  bin,  five  separate  samples  shall  be  taken  from  different 
portions  of  the  bin  and  not  more  than  two  from  the  same  level.  The  total  sample  shall 
not  be  less  than  ten  pounds. 

The  samples  shall  be  thoroughly  mixed  on  a  smooth  surface,  divided  in  halves, 
one-half  spread  evenly  over  the  other  half.  Repeat  this  operation  five  times.  The  mixed 
sample  shall  then  be  quartered  and  two  quarters  not  adjoining  rejected.  The  remain- 
ing quarters  shall  be  mixed  as  described  above,  five  times,  quartered  as  before  and 
two  quarters  rejected.  The  remaining  sample  shall  weigh  more  than  2.2  pounds  (1  kilo.) 
and  shall  be  placed  in  a  tight  receptacle,  marked  with  an  identifying  number  or  with 
the  name  of  the  material,  car  or  bin  number,  and  date  on  which  the  sample  was  taken. 

2.  Chemical  composition.  The  material  shall  conform  to  the  following  limits  of 
chemical  composition: 

Per  cent 

Silica,    not    less    than 99.60 

Potash  and  Soda,  not  more  than 15 

Iron  Oxides,  not  more  than 05 

Lime 10 

Magnesia,  not  more  than  10 

Alumina,    not    more    than 10 

3a.  Color.  The  flint  when  formed  into  a  standard  cone  and  fired  in  a  closed 
saggar  or  muffle  to  a  temperature  of  cone  8  shall  have  a  pure  white  color  both  on  the 
surface  and  the  interior  and  shall  be  easily  broken  by  the  fingers,  indicating  no  fusion. 
3b.  Fineness  of  grain.  One  hundred  grams  of  the  sample  after  being  dried  to 
constant  weight  at  105  degrees  C.  shall  be  tested  as  set  forth  in  paragraph  2b,  Feldspar 
Specifications41  and  the  residues  on  the  various  standard  sieves  shall  not  exceed  the 
maximum  totals  as  set  forth  in  the  following  table: 

Standard  Sieve  Number 

Grade     100  140  200  270       325   Total  residue 

1  0.10  0.2  1.50         2.00         5.0  8.8% 

2  0.50  1.0  2.50         3.50         6.5  14.0% 

39Cole,  L.  H.,  Silica  in  Canada  :  Part  I,  Canada  Dept.  of  Mines,  Mines  Branch  No. 
555,    p.   .31,    1923. 

40Am.    Ceramic   Soc.   Bull.,   vol.    2.   p.    166,   1923. 
4ildem,    p.    165. 


134  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

All  percentages  are  calculated  on  the  dry  basis. 

3c.  Moisture  content.  Unless  otherwise  specified  the  purchase  price  shall  be 
based  on  the  moisture  free  material  and  the  moisture  shall  be  determined  as  described 
under   paragraph   3,   Feldspar  /Specifications41 

3d.  Fusion  behavior.  Test  cones  shall  be  made  of  the  material  according  to 
standard  dimensions,  i.  e.  2%  inches  (75  mm.)  by  9/16  inch  (15  mm.)  across  the  base 
of  one  face.  An  organic  bond  as  dextrine  or  gum  arabic  is  permissible  to  insure  the 
cones  retaining  their  form  prior  to  fusion,  but  such  added  material  must  burn  out  com- 
pletely and  not  affect  the  color  of  the  material.  The  flint  when  made  into  cones  as 
described    above    shall    not    deform    before    cone    24. 

3e.  Shipping  conditions.  All  material  purchased  under  these  specifications  shall 
be    shipped    in   clean   closed   cars. 

4.  Rejection.  The  purchaser  reserves  the  right  to  reject  material  which  does  not 
conform  to  the  above  specifications  in  every  particular  and  to  return  rejected  material 
to  the  vendor  for  full  credit  at  price  charged  f.  o.  b.  point  of  delivery  specified  by  the 
purchaser. 

Those  parts  of  the  St.  Peter  sandstone  which  are  the  source  of  glass  sand 
furnish  a  supply  of  raw  sand  suitable  for  grinding  for  use  in  pottery  manu- 
facture. The  high  purity  of  the  sand  makes  it  particularly  well  suited.  Some 
of  the  ground  silica  produced  in  Illinois  is  sold  for  this  purpose. 

Poultry  and  Bird  Grit 

Small  quantities  of  sand  are  sold  as  poultry  grit  and  as  grit  for  pet  birds. 
A  coarse  sand  is  desirable  for  the  first  purpose  and  a  fine,  white  sand  for  the 
second.  No  preference  is  known  to  exist  between  round  and  angular  sands 
for  these  purposes. 

Sand  as  Railroad  Ballast 

Some  railroads,  particularly  those  which  do  not  have  a  ready  supply  of 
crushed  rock  or  gravel  close  at  hand,  use  sand  as  a  roadbed  base.  The  sand 
is  placed  on  the  subgrade  as  a  layer  about  six  inches  deep  and  later  covered 
with  crushed  stone,  cinders  or  gravel. 

Sand  for  use  as  railroad  ballast  should  be  coarse  enough  to  permit  ready 
drainage  of  water  and  should  not  contain  clay,  silt  or  organic  matter  in  such 
amounts  as  to  act  as  a  lubricant  when  wet  and  thus  cause  the  sand  to  slip  out 
from  beneath  the  ties  when  subject  to  the  weight  of  traffic.  Angular  sand 
may  possibly  have  a  slight  advantage  over  rounded  sand  since  the  movement 
of  rounded  grains  on  one  another  would  be  somewhat  easier  and  greater  than 
the  movement  of  angular  grains.  The  angular  grains  might  therefore  remain 
in  position  better  than  rounded  grains. 

Sand  for  Railroad  Fills 

Large  amounts  of  sand  are  used  by  railroad  companies  for  making  fills 
and  elevating  tracks  entering  and  leaving  large  cities.  No  specifications  of 
sand  for  this  purpose  were  noted  but  it  would  seem  that  such  sand  should  be 
dry  when  placed,  inasmuch  as  wet  sand  has  a  greater  volume  than  dry  sand, 


USES   OF   SAND  135 

and  that  it  should  pack  well  and  be  free  from  clay  and  earth  which  might 
later  wash  out  and  cause  the  embankment  or  fill  to  settle. 

The  railroads  in  the  vicinity  of  Chicago  use  largely  dune  and  lake  sand 
for  this  purpose.  The  St.  Peter  sand  would  also  doubtless  be  satisfactory,  but 
the  price  in  general  prohibits  its  use. 

Sand  for  Refractory  Mortars  and  Cements42 

Refractory  cements  and  mortars  are  employed  as  binders  for  fire  brick 
and  silica-brick  used  in  furnaces,  converters,  retorts  and  the  like  which  are  to 
withstand  high  temperatures.  They  are  also  used  as  a  patching  material  or 
plaster. 

Refractory  cements  and  mortars  usually  consist  of  a  refractory  material 
such  as  crushed  fire  brick,  sand  or  crushed  quartz ite,  held  together  with  a 
bond  of  fire  clay,  ball  clay,  lime,  Portland  cement,  or  sodium  silicate. 

Sand  used  for  refractory  cements  and  mortars  should  be  fine  and  highly 
refractory.  It  should  be  clean  and  free  from  fluxing  impurities.  The  St. 
Peter  sand  is  well  suited  for  this  purpose. 

Sand  for  Refractory  Ware 

A  mixture  of  fire  clay  and  sand  or  grog  is  used  for  making  crucibles, 
retorts,  saggars  and  the  like.  Inasmuch  as  this  ware  is  required  to  with- 
stand high  temperatures,  it  is  desirable  that  a  highly  refractory  sand,  free 
from  fluxing  impurities,  be  used.  In  general,  the  sand  used  is  finer  than  30 
mesh ;  for  retorts  and  saggars,  however,  it  may  be  a  little  coarser.  The  St. 
Peter  sand  is  well  suited  for  use  in  refractory  ware. 

Roofing  Sand 

Roofs,  especially  those  which  are  flat  or  nearly  flat,  are  sometimes  cov- 
ered with  tar  or  similar  substances  and  coated  with  sand.  The  sand  gives 
them  greater  weather-resisting  properties  and  in  a  measure  fireproofs  them. 
Sand  is  also  used  as  a  surfacing  material  for  roofing  papers. 

Roofing  sand  is  in  general  relatively  coarse.  The  color  is  usually  unim- 
portant. Both  rounded  and  angular  grains  are  used.  It  is  essential  that  the 
sand  be  clean  and  free  from  dust  so  that  it  may  hold  well  in  the  mastic. 

The  St.  Peter  sand  makes  a  very  good  roofing  sand.  One  company  uses 
sand  from  the  Ottawa  district  having  the  following  screen  analysis : 

Through  Retained  on  Per   cent 

20  mesh 40  mesh 51.7 

40  mesh 60  mesh 28.3 

60  mesh 80  mesh 9.1 

80  mesh 100  mesh 3.7 

100  mesh 200  mesh 5.8 

200  mesh 1.4 


42Searle,   A.   B.,  Refractory  materials  :  their  manufacture  and  uses,  p.   379-383,   1917. 


136-  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

Some  manufacturers  of  roofing  paper  use  a  finer  sand  than  the  above,  but 
in  general  a  sand  screening  about  the  same  as  glass  sand  is  used.  (See  also 
sand  for  tar  and  roofing  paper,  p.  141). 

Saggar  or  Placing  Sand43 

In  the  manufacture  of  white  ware  and  tile,  a  refractory  sand  is  used  as  a 
packer  in  the  saggars,  or  containers  in  which  the  ware  is  burned,  and  in  some 
cases  is  placed  between  the  pieces  to  keep  them  apart.  It  is  also  used  for  this 
last  purpose  with  heavy  clay  products  and  refractories. 

The  sand  used  for  white  ware  and  refractories  must  be  clean  and  low  in 
fluxes  and  iron.  Sand  to  be  used  with  dark  heavy  ware  need  not  be  so  pure. 
Placing  sand  is  produced  in  two  grades,  coarse  and  fine,  testing  approxi- 
mately between  10  and  40  mesh,  and  28  and  100  mesh  respectively.  Both 
rounded  and  angular  sands  are  used  but  the  former  are  preferred  since  they 
are  not  so  likely  to  stick  to  the  ware. 

The  St.  Peter  sand  makes  an  excellent  saggar  or  placing  sand  because  it 
is  highly  refractory  and  is  produced  clean,  free  from  fluxes  and  well  graded 
in  a  variety  of  sizes. 

Sand  for  Sandbags 

Bags  filled  with  sand  are  used  for  temporary  fortifications  in  military 
operations,  for  temporary  dams  and  levees,  and  as  ballast  for  ships,  balloons, 
and  airships.     There  are  no  general  specifications  for  sand  for  this  purpose. 

Sand-blast  Sand 

When  a  jet  of  sand  propelled  by  a  current  of  air  under  pressure  is 
allowed  to  come  in  contact  with  a  rough  object,  the  impact  of  each  grain 
produces  a  small  pit  or  depression.  The  impact  of  almost  countless  grains 
results  in  a  like  number  of  small  depressions  causing  a  gradual  wearing  away 
of  irregularities  and  projections  and  a  smoothing  and  polishing  of  the  surface 
which  the  grains  are  striking.  If,  however,  a  very  smooth  or  polished  surface 
is  exposed  to  a  sand  blast,  the  formation  of  innumerable  small  depressions 
roughens  the  surface  and  produces  a  dull  or  frosted  appearance.  This  is 
essentially  the  action  of  a  sand  blast.  The  sand  feeds  from  a  reservoir  into 
the  air  supply  and  the  two  emerge  together  from  a  nozzle  which  is  used  to 
direct  the  sand  against  the  object  being  abraded. 

Sand  blasting  is  used  for  a  wide  variety  of  purposes  some  of  which  are : 
removing  mill  scale  from  hot-rolled  sheets  and  bars ;  removing  furnace  scale 
from  f orgings  after  heat  treatment ;  cleaning  the  paint  from  steel  preparatory 
to  repainting ;  cleaning  stone  buildings  and  dressing  stone ;  cleaning  and 
smoothing  castings ;  giving  metal  to  be  enameled  or  plated  a  dull,  lusterless 


isWeigeJ,  Win.,  Special  sands:     IT.  S.  Bur.  Mines,  Serial  2G4G,  p.  7,  Oct.,  1924. 


USES  OF  SAND  137 

but  even  and  uniform  surface ;  producing  the  ground  or  frosted  surface  on 
glass ;  and  labeling  bottles  and  making  decorative  frosted  designs  on  glass 
ware. 

Sand-blast  sand  should  be  hard,  tough,  clean,  of  uniform  size  and  well 
graded  to  remove  large  grains  or  rubbish  which  might  clog  the  nozzle  of  the 
sand-blast  machine.  Both  angular  and  rounded  grains  are  used.  A  steel 
foundry  in  Oregon  specifies  as  blast  sand  a  high  silica  sand,  preferably  white, 
of  which  39  per  cent  is  retained  on  30  mesh,  85  per  cent  on  40  mesh,  97  per 
cent  on  50  mesh  and  99  per  cent  on  60  mesh.  Another  large  user  of  sand-blast 
sand  employs  a  white  high  silica  sand  with  rounded  grains  of  such  size  that 
96  to  98  per  cent  will  be  retained  on  a  40  mesh  sieve. 

The  St.  Peter  sand  as  produced  in  Illinois  is  somewhat  fine  as  compared 
with  other  sands  for  sand  blasting,  but  because  of  its  uniform  sizes  and  the 
natural  density  and  toughness  of  its  grains,  it  stands  up  very  well  as  a  blast 
sand  and  is  reported  to  give  superior  results. 

Sand  for  Sand  Baths 

In  chemical  laboratories  containers  of  hot  sand  are  used  to  hold  vessels 
which  are  to  be  heated  gradually  and  without  direct  contact  with  the  flame. 
Sand  for  this  purpose  should  be  free  from  dust  and  any  impurities  which 
break  up  or  decrepitate  on  heating.  In  general  a  medium  sized,  high  silica 
sand  is  preferred. 

Sand- clay  Roads 

As  the  name  suggests,  a  sand-clay  road  consists  of  a  mixture  of  sand 
and  clay.  The  amount  of  clay  present  is  generally  about  that  required  to  fill 
the  voids  in  the  sand.  This  mixture  is  effected  by  combining  clay  with  the 
sand  of  a  sandy  toad,  by  mixing  sand  with  the  clay  of  a  clay  road,  or  by 
surfacing  a  pre-existing  road  with  a  mixture  of  sand  and  clay.  In  the  first 
case  mentioned,  the  control  which  can  be  exerted  on  the  quality  of  the  sand 
in  the  road  is  minor.  In  the  last  two  cases,  however,  it  is  possible  to  specify 
sand  of  a  certain  quality. 

In  general  a  rather  coarse  silica  sand  free  from  large  amounts  of  mica  is 
preferred  for  use  in  sand-clay  roads.  According  to  Baker,44  "for  the  best 
results,  not  less  than  45  per  cent  nor  more  than  60  per  cent  of  the  sand  should 
be  finer  than  that  caught  on  a  standard  No.  10  sieve,  and  coarser  than  that 
caught  on  a  No.  60  sieve ;  and  that  caught  on  Nos.  20,  40,  and  60  sieves  should 
be  about  equal  to  each  other." 

The  St.  Peter  sandstone  in  Illinois  is  in  general  too  fine  to  pass  the  above 
specifications  for  size.    It  is,  however,  a  usable  sand  in  other  respects. 


44Baker.   I.   O.,   A  treatise   on  roads   and  pavements,   p.    144,   New   York,   J.   Wiley  & 
Sons,   1920. 


138  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

Sand  for  Sand  Finishing  Painted  Surfaces 

In  regions  where  buildings  are  subject  to  sand  storms,  such  as  the  Pacific 
coast,  sand  is  used  as  a  finish  on  painted  surfaces  to  make  them  resistant  to 
the  abrasive  effects  of  the  sand  of  the  sand  storms.  White,  sharp,  even- 
grained  sand  is  preferred  for  this  purpose,  because  the  sharp  grains  hold  well 
in  the  paint  and  the  angular  faces  of  the  grains  produce  a  pleasing  glistening- 
effect.45 

Sand  is  also  used  to  give  a  rough  effect  on  painted  walls  either  to  prevent 
writing  and  scratching  on  them  or  to  secure  a  stone-like  surface.  Such  sand 
should  be  free  from  foreign  material  and  impurities  but  other  specifications 
depend  primarily  on  the  effect  desired.  The  St.  Peter  sand  is  very  suitable 
for  finishing  purposes  because  it  is  produced  in  uniform  grades  and  is  very 
clean. 

Sand  for  Sand  Finishing  Plaster  Walls 

Sand  is  applied  to  plaster  walls  to  secure  a  sand  finish.  The  size  of  the 
sand  used  and  the  manner  in  which  it  is  applied  depend  on  the  texture  and 
effect  desired.  The  sand  should,  however,  be  even  grained  and  uniform 
in  color. 

The  St.  Peter  sand  is  widely  used  in  the  middle  west  for  this  purpose 
because  it  has  an  even  color  and  is  purchasable  well  sized. 

Sand  Paper 

At  one  time  sand  was  used  rather  commonly  as  the  abrasive  surfacing  of 
sand  paper.  At  the  present  time,  however,  crushed  garnet,  quartz,  quartzite, 
or  artificial  abrasives  have  largely  replaced  sand.  The  abandonment  of  natural 
sands  in  favor  of  garnet  and  artificial  abrasives  has  been  largely  due  to  the 
greater  angularity  and  sharpness  and  the  superior  hardness  of  these  materials. 

Sand  for  Sand  Piles  (See  sand  for  sand  tables  and  sand  piles,  p.  139) 

Sand  for  Sand  Seals 

Sand  seals  are  used  in  place  of  water  seals  where  the  latter  cannot  be 
employed  because  of  the  high  temperatures  to  which  they  would  be  subjected. 
Sand  seals  are  used  on  manhole  and  flue  covers,  and  dampers  of  kilns  and 
furnaces  and  serve  to  prevent  the  escape  of  heat  and  gases  around  the  edges 
of  the  movable  parts.  The  chief  requirements  of  sand  for  this  purpose  are 
that  it  be  highly  refractory,  fine  and  preferably  round-grained  so  that  the 
grains  may  readily  roll  into  and  fill  any  small  openings  in  the  seal. 

The  St.  Peter  sand  is  very  suitable  for  sand  seals  inasmuch  as  it  meets 
all  of  the  foregoing  requirements. 


45Condra,    G      E.,    The    sand    and    gravel     resources     and     industries      of     Nebraska: 
Nebraska  Geol.  Survey,  vol.  '.),  pt.  1,  p.  201,  1911. 


USES    OF   SAND  139 

Sand  for  Sand  Tables  and  Sand  Piles 

A  clean,  relatively  fine,  white  sand  is  used  on  sand  tables  and  for  sand 
piles  in  schools  and  playgrounds.  For  the  former  it  is  desirable  that  the  sand 
be  free  from  clay ;  for  the  latter,  however,  this  is  not  generally  essential  but 
the  clay  content  should  be  low.  The  white  St.  Peter  sand  would  serve  excel- 
lently for  these  purposes. 

Sawing  Sand  (See  cutting  and  sawing  sand,  p.  Ill) 
Scouring  Sand 

Sand  is  used  to  some  extent  as  a  scouring  agent  for  cleaning  metal  and 
other  articles.  Sand  for  this  purpose  is  sometimes  called  "silver"  or  "livery" 
sand.  The  former  is  generally  a  white  sand ;  the  latter  commonly  yellow. 
Very  fine  sand  may  also  be  used  as  an  ingredient  of  metal  polishes. 

It  is  desirable  that  sand  for  scouring  purposes  be  fine  and  evenly  graded. 
Both  angular  and  rounded  grains  give  satisfactory  results  though  the  former 
are  probably  somewhat  more  rapid  in  their  action. 

Setting  Sand 

Setting  sand  is  sand  used  in  brick  kilns  as  a  cushion  on  which  bricks  to 
be  fired  are  placed.  It  is  also  placed  between  the  bricks  to  prevent  their 
sticking  together.  Three  Illinois  brick  companies  state  that  they  have  no 
strict  specifications  for  the  sand.  They  do  require,  however,  that  the  sand  be 
free  from  pebbles  and  fine  enough  so  as  not  to  indent  noticeably  the  surface 
of  the  brick  resting  on  it.  The  sand  also  should  be  capable  of  standing  a  heat 
similar  to  that  used  in  burning  the  brick  without  fusing  and  should  be  dry  and 
free  from  any  impurities  which  might  discolor  the  brick.  One  of  the  com- 
panies mentioned  uses  glass  sand  from  Ottawa  and  finds  it  very  satisfactory 
because  it  is  dry,  white  and  of  a  uniform  size. 

Inasmuch  as  the  St.  Peter  sand  is  highly  refractory,  and  is  produced  well 
graded  and  dry,  it  is  used  in  many  places  as  a  setting  sand. 

Sand  for  Sidewalks 

In  the  construction  of  concrete  and  brick  sidewalks  the  sub-base  com- 
monly consists  of  cinders  or  gravel.  Some  of  the  sub-bases  are  covered  with 
a  cushion  of  sand  on  which  the  brick  or  cement  is  laid.  Practically  any  sand 
which  packs  well  is  suitable  for  this  purpose. 

Sand  for  Making  Silicon 

Silicon  is  made  in  an  electric  furnace  by  heating  sand  or  quartzite  with 
carbon  (coke).    The  reaction  is  as  follows: 

Si02  +  2C  ->  Si  +  2CO 
The  sand  should  be  fine  and  of  very  high  chemical  purity. 


140  THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

Sand  for  Use  in  Soaps 

Ground  or  fine  sand  is  used  as  a  scouring  agent  or  filler  in  soaps. 

Sand  for  Making  Sodium  Silicate  (Water  Glass) 

In  the  manufacture  of  sodium  silicate,  sand  in  the  ground  form  is  used 
to  furnish  the  silicate  portion  of  the  compound.  The  high  chemical  purity  of 
the  St.  Peter  sand  of  the  Ottawa  district  makes  it  very  desirable  for  this 
purpose  and  it  is  used  widely.  One  company  purchases  in  ground  St.  Peter 
sand  which  meets  the  following  specifications : 

2  per  cent  through  100  mesh    (the  finer  the  better) 
50  per  cent  through     50  mesh 
90  per  cent  through     30  mesh 

It  should  be  free  from  dirt  and  dry.     The  color  of  the  sand  must  be  white. 

The  chemical   requirements   are   as  follows: 

Silica    (Si02)    Minimum  permissible  99.5  per  cent 

Iron  oxide  (Fe003)    and  alumina  (A1203) Maximum  permissible     0.25  per  cent 

Lime    (CaO)    and  magnesia    (MgO) Maximum  permissible       0.0  per  cent 

Loss  on  ignition 0.25  per  cent 

Minimum  permissible  melting  point  1600°C. 

Standard  Ottawa  Sand  (See  testing  sand,  p.  141) 
Sand  for  Stone-block  Pavements 

The  modern  type  of  stone-block  pavement  consists  most  commonly  of  a 
concrete  base,  a  sand  or  mortar  cushion  and  a  wearing  course  of  stone  blocks. 
The  sand  cushion  when  used  is  commonly  2  or  3  inches  thick.  The  joints 
between  the  stone  are  filled  with  cement  grout,  pea  gravel,  or  sand.  The  last 
two  materials  are  commonly  mixed  with  a  bituminous  mastic  such  as  tar 
or  pitch. 

The  sand  used  in  the  concrete  base  and  cement  grout  should  in  general 
pass  the  same  specifications  as  given  for  those  parts  of  the  road  under  Brick 
Pavements.  The  sand  cushion  should  consist  of  clean,  fine  sand,  all  of  which 
will  pass  34-inch  mesh.  The  sand  used  with  the  tar  or  pitch  filler  should  be 
clean  and  should  pass  a  20-mesh  screen.46 

Sand  for  Stucco 

The  term  "stucco"  is  applied  to  all  forms  of  exterior  plaster  work  and 
to  certain  special  types  of  interior  plastering.  The  exterior  stucco  is  com- 
monly a  cement  plaster;  the  interior  stucco  may  be  cement,  lime  or  gypsum 
plaster.  In  general  stucco  contains  about  one  part  of  binder  to  three  parts 
of  sand  or  other  fine  aggregate.  The  specifications  of  sand  for  various  types 
of  plasters  are  discussed  under  the  use  of  sand  for  plastering  (p.  131). 


40Baker,  I.  O.,  A  treatise  on  roads  and  pavements,  p.  5S5,  New  York,  J.  Wiley  &  Sons, 

1920. 


USES  OF   SAND  141 

Sand  in  Sweeping  Compounds 

Because  of  its  incoherency,  sand  is  used  in  some  sweeping  compounds  to 
give  them  a  body  which  will  hold  the  oil  or  other  dust  palliative  they  contain. 

Sand  in  Tar  and  Roofing  Paper47 

In  the  manufacture  of  tar  paper,  sand  is  used  as  a  coating  to  prevent  the 
sticking  of  the  paper.  Clean,  white,  dustless  sand  about  65  mesh  in  size  is 
commonly  used.    Ground  sand  is  also  sometimes  used  for  this  purpose. 

Sand  for  Terrazzo  Floors 

In  laying  certain  types  of  terrazzo  floors  it  is  recommended48  that  a  sand 
bed  one-quarter  inch  thick  be  laid  on  a  base,  that  the  sand  be  covered  with  tar 
paper  and  that  the  latter  in  turn  be  covered  by  a  mortar  composed  of  one  part 
Portland  cement  and  four  parts  of  coarse  sand.  When  the  mortar  has  set 
the  terrazzo  is  laid  over  it. 

Sand  for  Testing  Detonators49 

In  testing  the  efficiency  of  detonators  for  explosives  a  test  known  as  the 
sand  test  is  sometimes  employed.  It  consists  of  immersing  the  detonator  in 
sand  and  determining  the  amount  of  powdered  sand  produced  by  firing. 

Sand  for  making  this  test  must  be  practically  pure  quartz  and  all  pass 
20-mesh  sieve  and  be  retained  on  a  30-mesh  sieve.  Standard  Ottawa  sand 
meets  these  specifications. 

Testing  Sand:     Standard  Ottawa  Sand 

Standard  Ottawa  sand  is  used  for  testing  the  strength  of  cements  and  as 
a  laboratory  standard  in  physical  tests  of  other  sands.  Standard  Ottawa  sand 
is  very  carefully  screened  so  that  all  the  grains  pass  a  20-mesh  sieve  but  are 
retained  on  a  30-mesh  sieve. 

Tumbling  Sand 

Tumbling  barrels  containing  sand  used  for  scouring  and  polishing  small 
metal  articles  which  are  to  be  plated  or  lacquered.  The  size  of  the  sand  used 
in  general  depends  on  the  character  and  size  of  the  pieces  being  cleaned.  A 
sand  capable  of  withstanding  wear  is  essential  for  this  purpose  and  high  silica 
sands  are  commonly  used. 


47Teas,  L.  P.,  Preliminary  report  on  the  sand  and  gravel  deposits  of  Georgia;  Geol 
Survey  of  Georgia  Bull.   37,  p.   95,   1921. 

48Sweets   Architectural   Catalogue,    20th   ed.,    p.    501,    New   York,    1925-1926. 
49Marshall,   Arthur,   Explosives,   2d  ed.,   vol.   2,   p.   530,   Philadelphia,    1917. 


1+2  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

Sand  for  Making  Water  Glass   {See  sand  for  making  sodium  silicate, 

p.  140) 

Sand  for  Welding 

Sand,  usually  finer  than  50-mesh,  is  sprinkled  on  the  surfaces  of  pieces 
of  iron  to  be  welded  and  when  heated,  acts  as  a  flux  and  forms  with  the  rust 
or  scale  on  the  iron  an  iron-silica  compound  which  is  easily  eliminated  from 
the  weld  by  hammering.  In  this  way  a  good  metallic  contact  is  facilitated 
and  the  probability  of  a  permanent  weld  increased.  Inasmuch  as  the  silica  is 
the  effective  agent  in  this  process,  a  high  silica  sand  is  desirable.  The  St. 
Peter  sand,  because  it  is  a  high  silica  sand  and  fine  grained,  is  a  very  good 
welding  sand.  St.  Peter  sand  sold  by  one  producer  in  the  Utica  district  gave 
the  following  sieve  analysis : 

Through  Retained  on  Per  ceni 

28  mesh 3 5  mesh 7 

35  mesh 48  mesh 41 

48  mesh 65  mesh 20 

65  mesh 100  mesh 19 

100  mesh 150  mesh 10 

150  mesh 3 

Sand  for  Wood-block  Pavements 

The  common  type  of  modern  wood-block  pavement  consists  of  a  concrete 
base,  a  bedding  course  of  sand,  mortar  or  tar  sprinkled  with  sand,  and  a 
wearing  course  of  wood  blocks.  The  joints  between  the  blocks  are  filled  with 
sand,  cement  grout,  or  bitumen.  When  bitumen  is  used,  the  surface  of  the 
filled  joints  is  commonly  covered  with  a  layer  of  coarse  sand  to  prevent  the 
bitumen  from  sticking  to  passing  wheels. 

The  specifications  for  the  sand  used  in  the  various  parts  of  wood-block 
pavements  are  in  general  essentially  the  same  as  those  for  corresponding 
parts  of  brick  pavements.     (See  Brick  Pavements,  p.  107.) 


CHAPTER    VI.— SAMPLING    AND    TESTING    OF 
ST.  PETER   SAND 

Value  of  Tests 

Before  sampling  of  the  St.  Peter  sandstone  was  undertaken,  the  value  of 
samples  was  seriously  considered.  A  number  of  sieve  analyses  were  available, 
but  these  were  for  the  most  part  of  certain  grades  of  sand.  Such  analyses  of 
the  crude  sand  as  were  obtainable  were  taken  in  different  fashions  by  dif- 
ferent individuals  and  were  therefore  liable  to  various  errors  as  far  as  their 
use  for  comparative  purposes  was  concerned.  It  seemed  worth  while,  there- 
fore, from  an  economic  and  scientific  standpoint,  to  undertake  a  sampling- 
campaign  of  sufficient  magnitude  to  indicate  the  following :  ( 1 )  the  regional 
variations  in  the  texture  of  the  sandstone;  (2)  the  magnitude  of  the  local 
variations  in  texture,  that  is  within  a  given  quarry  or  similar  unit;  (3)  the 
variation  in  texture  in  different  parts  of  the  same  bed;  (4)  the  content  and 
distribution  of  the  yellow  iron  oxide;  (5)  the  distribution  of  the  clay  content; 
(6)  the  variations  in  the  different  types  of  crude  sand  produced.  The  bear- 
ing of  the  results  of  the  tests  on  these  questions  is  discussed  in  Chapter  III. 
Suffice  it  to  say  here  that  the  tests  on  the  samples  indicate  a  considerable 
variation  in  the  texture  of  the  sandstone  even  in  limited  areas.  Therefore 
analyses  of  the  sand  in  any  given  quarry  are  not  empirically  representative  of 
the  deposit  as  a  whole.  As  is  true  in  sampling  any  variable  mineral,  deposit 
the  samples  indicate  the  character  of  the  sand  merely  at  the  places  where  they 
were  taken. 

Sampling  the  Sandstone 

general  statement 

In  sampling  a  sandstone  like  the  St.  Peter  many  problems  arise,  the  chief 
of  which  is  the  availability  of  the  face  to  be  sampled.  Most  of  the  quarries 
have  faces  50  feet  or  more  in  height  which  could  be  sampled  only  by  working 
from  the  pile  of  loose  sand  which  generally  is  present  against  the  quarry  face 
as  the  result  of  blasting  operations.  Where  this  loose  sand  was  absent  it  was 
rarely  possible  to  sample  and  generally  necessary  to  wait  until  after  primary 
blasting  had  formed  the  requisite  pile.  In  a  number  of  quarries  it  was  im- 
possible to  reach  the  uppermost  beds  of  sand  and  therefore  these  are  not  rep- 
resented in  the  sample.  The  samples  were  taken,  however,  to  represent  the 
sand  from  the  entire  face  insofar  as  possible. 

143 


144  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


KINDS  OF   SAMPLES 


According  to  the  purpose  of  a  sample  and  to  the  cementation,  availability 
and  character  of  the  deposit,  five  different  types  of  samples  were  taken. 

( 1 )  Face  sample.  A  face  sample  is  one  which  was  taken  from  a  quarry 
face  or  an  outcrop  by  first  removing  any  weathered  sandstone  present  and 
then  collecting  the  sand  from  a  channel  a  foot  wide  and  an  inch  deep,  extend- 
ing the  entire  height  of  the  exposure.  As  it  was  generally  impossible  to 
sample  a  quarry  face  by  a  single  channel,  it  was  often  necessary  to  sample 
from  a  series  of  successively  lower,  offset  channels,  each  beginning  at  the  same 
horizon  as  that  at  which  the  channel  above  it  had  left  off.  A  chisel  pointed 
hammer  was  generally  used  for  loosening  and  cutting  down  the  sand.  A  large 
piece  of  canvas  was  placed  conveniently  at  the  foot  of  the  channel  to  catch 
the  sand  as  it  fell.  Periodically  the  contents  of  this  canvas  were  conveyed  to 
the  floor  of  the  quarry  and  transferred  to  another  large  piece  of  canvas  on 
which  the  sand  from  the  entire  cut  was  collected. 

(2)  Chip  sample.  In  some  exposures  the  St.  Peter  was  so  firmly 
cemented  that  it  was  impracticable  to  dig  a  channel.  The  sandstone  was  sam- 
pled therefore  by  first  removing  as  far  as  possible  the  weathered  portion  and 
then  taking  chips  of  approximately  equal  size  from  the  entire  height  of  the 
exposure.  It  was  thought  that  the  mechanical  destruction  of  the  individual 
grains  would  be  less  in  samples  so  taken  than  in  a  face  sample,  because  of  the 
pounding  of  the  sandstone  necessary  to  obtain  the  latter.  The  chips,  like  the 
face  sample,  were  collected  on  canvases.  Before  reducing  the  sample  to  the 
size  desired  for  shipment  the  lumps  were  thoroughly  disintegrated  by  hitting 
them  with  the  flat  side  of  a  shovel  or  with  a  hammer. 

(3)  Bed  sample.  The  purpose  of  bed  samples  was  to  determine  the 
character  of  the  sand  in  a  given  bed.  They  were  taken  in  the  same  fashion 
as  the  face  samples. 

(4)  Grab  sample.  In  one  quarry  it  was  impossible  to  obtain  a  sample 
of  the  sand  from  the  quarry  face  because  of  its  precipitousness.  A  "grab" 
sample  was  therefore  secured  by  taking  handfuls  of  sand  from  various  parts 
of  loaded  railroad  cars.  The  same  number  of  handfuls  was  taken  from 
each  car. 

(5)  Plant-run  samples.  These  samples  were  taken  to  show  how  the 
sand  actually  produced  by  a  given  plant  varied  from  the  average  analysis 
shown  by  the  face  sample  which  was  taken  at  about  the  same  time.  The  plant- 
run  sample  was  taken  directly  from  the  conveyor  belt  carrying  the  sand  away 
from  the  driers. 

SPLITTING  THE  SAMPLE  IN  THE  QUARRY 

When  assembled  on  the  collecting  canvas  the  face  samples  weighed  be- 
tween about  200  and  800  pounds ;  the  weight  depending  on  the  height  of  the 


SAMPLING  145 

face  sampled.  In  order  to  reduce  a  sample  to  the  requisite  30  or  40  pounds,  a 
sample  splitter  or  riffler  of  the  Jones  type  was  used.  The  riffler  consisted  of 
a  galvanized  iron  frame  12  inches  long,  7  inches  wide  and  8  inches  deep,  with 
a  total  of  6  two-inch  openings  discharging  alternately  in  opposite  directions. 
The  floors  of  these  openings  were  inclined  at  an  angle  of  about  45°  and 
formed  a  sort  of  chute.  The  discharge  openings  of  the  chutes  were  2  by  3 
inches.  A  handle  was  attached  at  each  end  of  the  riffler  and  a  hook  at  the 
middle  of  the  bottom  of  each  end  of  the  frame.  In  splitting  the  sample  a 
piece  of  canvas  was  fastened  to  the  hooks  at  the  ends  of  the  riffler  by  means 
of  properly  spaced  eyelets.  The  riffler  was  held  by  a  member  of  the  field 
party  or  placed  upon  a  conveniently  situated  rock.  The  lumps  in  the  sand  on 
the  collecting  canvas  were  crushed  and  the  sand  was  mixed  as  thoroughly  as 
possible  by  shoveling  about,  and  then  fed  with  a  shovel  8  inches  wide  into 
the  riffler.  The  sand  was  so  fed  that  the  bulk  of  it  fell  into  the  four  center 
openings  or  chutes.  Any  sand  dropping  off  the  sides  of  the  shovel  fell  into 
the  two  end  chutes.  By  this  method  the  sample  was  halved  or  split ;  one  half 
was  caught  upon  the  canvas  hooked  to  the  riffler  and  the  other  half  fell  to 
the  ground  and  was  discarded.  This  process  was  repeated  until  the  sample 
was  the  required  size. 

The  same  splitting  process  was  applied  to  samples  other  than  face  sam- 
ples, which  were  initially  too  large  for  shipment. 

SHIPPING   THE    SAMPLE 

The  final  sample  consisted  of  between  20  and  35  pounds  of  sand.  It  was 
put  into  a  heavy  paper  bag  along  with  an  identification  tag.  The  bag  was 
securely  tied  and  then  put  into  a  cement  sack  which  was  labeled  on  the  out- 
side for  shipment  by  express.  In  the  course  of  transit  some  of  the  paper 
sacks  broke  but  the  leakage  through  the  cement  sacks  was  very  small. 

SPLITTING   THE   SAMPLE   IN    THE   LABORATORY 

For  purposes  Of  analysis  it  was  necessary  to  split  the  field  sample  to  100 
or  200  grams.  For  this  operation  an  8-inch  tin  funnel  with  a  discharge 
opening  of  %  incn  was  used.  In  the  small  end  of  the  funnel  was  a  metal 
partition  placed  so  as  to  exactly  divide  the  discharge  opening  into  two  halves. 
The  partition  was  extended  below  the  funnel  to  form  two  chutes  discharging 
in  opposite  directions.  The  sand  from  the  chutes  was  collected  in  pails.  Be- 
fore the  sand  was  put  into  the  splitter  any  small  lumps  remaining  in  it  were 
crushed  by  rolling  gently  with  a  rolling  pin  on  a  board  and  the  sample  was 
thoroughly  mixed  and  screened  on  a  14-mesh  sieve  to  remove  sticks  or  lumps 
of  pyrite  which  might  clog  the  discharge  of  the  funnel.  Although  it  took 
some  time  to  split  a  sample  with  this  device  because  of  the  smallness  of  the 
discharge  opening,  the  funnel  was  large  enough  to  require  only  occasional 


146  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

refilling  and  therefore  very  little  attention.  In  falling  from  the  chutes  the 
sand  from  some  of  the  samples  which  contained  a  high  percentage  of  clay 
raised  small  amounts  of  dust.  In  splitting  sands  of  this  type  the  pails  were 
covered  with  pasteboard  lids  having  openings  just  large  enough  to  accommo- 
date the  discharge  ends  of  the  chutes. 

In  order  to  test  the  accuracy  of  this  splitter  a  forty-pound  sample  was 
run  through  it  and  the  two  halves  weighed.  One  of  the  halves  weighed  two 
ounces  more  than  the  other.  It  was  felt  that  an  error  of  this  size  was  within 
the  permissible  limits  of  error  for  splitting  a  sample.  In  order  to  test  the 
splitter  further  a  given  sample  of  sand  was  run  through  until  about  100  grams 
was  cut  down.  The  same  bulk  sample  was  run  through  the  splitter  again  and 
another  100-gram  sample  isolated.  Both  samples  were  sieved  according  to 
the  regular  procedure  and  the  results  are  the  two  analyses  of  sample  2  (Table 
10).  Examination  shows  these  analyses  to  be  very  closely  similar  for  the 
maximum  variation  between  them  is  only  1.4  per  cent.  Sample  28  was  treated 
in  the  same  fashion  and  the  two  analyses  given  for  it  have  a  maximum  varia- 
tion of  1.7  per  cent. 

Mechanical  Analysis  of  Samples  and  Tables  of  Results 
methods  of  testing  the  sand 

Only  two  tests  were  generally  made  on  the  samples  of  St.  Peter  sand, 
namely  the  fineness  or  sieve  test,  and  a  test  for  the  determination  of  the 
amount  of  clay  substance  present.  Only  some  of  the  samples  were  analyzed 
to  determine  their  iron  content. 

In  testing  for  fineness  and  clay  substance  the  method  recommended  by 
the  American  Foundrymen's  Association1  was  followed  in  a  general  way. 
According  to  these  tests  a  50-gram  sample  of  thoroughly  dried  sand  is  placed 
in  a  one-quart  jar  containing  475  cc.  of  water  and  25  cc.  of  standard  solution 
of  sodium  hydroxide  and  agitated  in  a  mechanical  shaker  for  an  hour.  After 
shaking,  the  sand  and  water  is  allowed  to  stand  for  ten  minutes  and  the  sus- 
pended material  is  siphoned  off.  More  water  is  added  and  siphoned  off  after 
five  minutes.  This  process  is  repeated  until  the  water  remains  clear  at  the 
end  of  the  five-minute  settling  period.  The  material  siphoned  off  is  the  clay 
substance  and  its  quantity  is  calculated  by  subtracting  the  weight  of  the  sand 
remaining  from  50  grams. 

In  testing  the  St.  Peter  samples  slight  departures  were  made  from  the 
general  procedure  described  above.  A  sample  of  about  100  instead  of  50 
grams  was  used  because  it  was  found  that  the  larger  sample  gave  better  re- 
sults in  indicating  the  amount  of  the  20-mesh  sand  and  the  amount  of  sand 
passing  the  270-mesh  sieve.     The  sample  was  not  reduced  to  any  standard 


lAmerican  Foundrymen's  Assoc  Hull..  June  1,  1024.  The  complete  procedure  is 
tfivon  in:  Littlefield,  M.  S.,  Natxiral-bonded  molding  sand  resource's  of  Illinois:  Illinois 
Stale    Geol.    Survey    P>ull    50,    pp.    20-r>;{,    192."). 


MECHANICAL    ANALYSES 


147 


Table  9a. — Constants  for  Tyler  Standard  Screen  Scale  Sieves2 
(Arranged  according  to  sieve  openings) 


Sieve 

Apertures  Tyler  standard 
screen  scale  sieves 

Average  diameter  of  product 

Inches 

Millimeters 

Inches 

Millimeters 

1  in. 

*A  in. 
H  in.     . 
3A  in, 

3  M 

4  M 
G  M 
8  M 

10  M 

14  M 

20  M 

28  M 

35  M 

48  M 

65  M 
100  M 
150  M 
200  M 
270  M 

1.050 

0.742 

0.525 

0.371 

0.263 

0.185 

0.131 

0.093 

0.065 

0.046 

0.0328 

0.0232 

0.0164 

0.0116 

0.0082 

0.0058 

0.0041 

0.0029 

0.0014« 

26.67 
18.85 
13.33 
9.423 
6.680 
4.699 
3.327 
2.362 
1.666 
1.178 
0.833 
0.589 
0.417 
0.295 
0.208 
0.147 
0.104 
0.074 
0.037 

0.896 

0.634 

0.448 

0.317 

0.224 

0.158 

0.112 

0.079 

0.056 

0.0394 

0.0280 

0.0198 

0.0140 

0.0099 

0.0070 

0.0050 

0.0035 

0.0022 

22.76 
16.09 
11.377 
8.052 
5.690 
4.013 
2.845 
2.014 
1.422 
1.000 
0.711 
0.503 
0.356 
0.252 
0.178 
0.126 
0.089 
0.056 

a  Assumed. 

weight  before  sieving  because  it  was  thought  that  the  sample  taken  from  the 
splitter  after  the  last  reduction  was  as  representative  of  the  whole  sample  as 
possible  and  that  the  addition  or  subtraction  of  any  sand  would  destroy  the 
representativeness  of  the  sample.  The  extraction  of  the  clay  substance  was 
carried  out  as  described  above  except  that  about  twice  the  volume  of  sodium 
hydroxide  solution  was  used.  The  clay  was  saved  and  caused  to  flocculate 
by  adding  a  little  concentrated  sodium  hydroxide  solution.  The  flocculated 
clay  settled  rapidly  so  that  it  was  an  easy  matter  to  get  rid  of  most  of  the 
water  by  decantation.  The  clay  was  collected  on  a  filter  paper  and  weighed. 
Inasmuch  as  the  plant-run  samples  were  free  from  clay  as  obtained  the  clay 
was  not  calculated  as  a  part  of  any  of  the  sieve  analyses  in  order  that  all  the 
sieve  analyses  might  be  comparable.  In  general,  no  clay  determinations  were 
made  on  samples  taken  from  natural  outcrops,  because  of  the  possibility  that 
rain  wash  would  probably  have  removed  much  of  the  clay  or  else  introduced 
it  into  the  sandstone  from  the  overburden  and  that  the  analyses  would  there- 
fore be  unreliable  so  far  as  the  clay  is  concerned.  The  sand,  freed  of  clay, 
was  dried  and  sieved  for  15  minutes  in  a  rotap  testing  sieve  shaker.  Tyler 
Standard  Screen  Scale  sieves  were  used  for  the  sieving.  All  analyses  were 
made  with  the  same  set  of  sieves,  and  the  results  are  therefore  comparable. 
T able  9a  gives  the  constants  for  Tyler  Standard  Screen  Scale  Sieves  and  the 
average  diameter  of  the  product. 


1914 


2Taggart,  A.   F.,    The  work  of  crushing:     Am.   Inst.   Min.   Eng.   Bull.    85,   p.    161,   Jan., 


Catalogue  48,  W.   S.  Tyler  Co.,  Cleveland,   Ohio, 


37,    1924. 


148  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 


RESULTS   OF    MECHANICAL   ANALYSIS 


Tables  10  and  11  give  the  results  of  the  sieve  tests  and  the  clay  determina- 
tions. The  results  in  Table  10  are  given  in  per  cent  by  weight;  in  Table  11 
the  compositions  of  the  various  samples  are  expressed  in  per  cent  by  number 
of  grains. 

It  is  of  interest  to  note  in  connection  with  the  tables  that  there  is  rarely 
accordance  between  the  analyses  of  the  face  and  plant-run  samples  from  the 
same  quarries.  A  lack  of  accordance  is  rather  to  be  expected  since  the  sand 
discharging  from  the  drier  may  represent  only  a  certain  part  or  parts  of  the 
quarry  face.  The  plant-run  samples  were  taken  to  establish  this  fact  and  to 
determine  how  representative  such  samples  were  of  the  deposit  or  working 
face  as  a  whole. 

Table  10  includes  besides  the  sieve  analysis  the  fineness  modulus.  (See 
pp.  157-158.)  The  other  figures  for  expressing  fineness  by  a  single  number 
can  be  calculated  from  the  sieve  analyses  according  to  the  methods  described 
on  pages  155-157. 

Tests  for  Angularity 
method  of  procedure 

In  common  parlance  the  St.  Peter  is  generally  spoken  of  as  a  rounded 
sand,  for  the  most  part  correctly  so.  So  far  as  is  known,  however,  no  results 
have  been  published  comparing  the  angularity  or  roundness  of  the  grains  of 
the  Illinois  St.  Peter  from  different  outcrops  and  horizons  in  the  State ;  nor 
are  such  data  available  concerning  this  sandstone  in  comparison  with  other 
sandstones.  The  specifications  for  certain  uses  of  sand  require  that  it  be 
angular  but  the  determination  of  what  constitutes  an  angular  sand  is  left  to 
individual  opinion  because  of  lack  of  definite  means  of  determining  and  ex- 
pressing this  property.  It  has  seemed  worth  while,  therefore,  to  consider 
means  for  measuring  angularity  and  to  suggest  a  mechanical  method  for 
determining  it. 

Trowbridge  and  Mortimore3  recently  suggested  a  method  of  determining 
angularity  by  optical  comparison  with  a  more  or  less  arbitrary  set  of  standard 
angularity  grades  consisting  of  representative  grains.  Sandstone  beds  have 
been  correlated  successfully  from  well  cuttings  by  this  method.  However,  the 
procedure  involves  individual  opinion  which  makes  it  liable  to  error.  Another 
method  of  determining  the  roundness  of  sand  grains  has  consisted  of  rolling 
them  down  an  incline  on  to  some  flat  surface  and  measuring  the  distance 
they  roll.  This  procedure,  or  variations  of  it,  depends  for  its  results  princi- 
pally on  the  velocity  which  the  grains  attain  in  their  descent.  Obviously  an 
egg-shaped  grain  might  attain  the  same  velocity  as  a  perfectly  spherical  grain 


:;  Trowbridge,   A  C,   and   Mortimore,   M.   FJ.,    Correlation   of  oil   sands   by   sedimentary 
analysis:      Kcon.     fjoolopy,     vol.     2(1.     pp.     400-423.     1025. 


149 


Sample 

No.  . 


N 


10. 
11. 

12. 
13. 

13a. 

14. 

15. 

16. 

17. 

18. 

19. 

20. 

21. 


24. 

25. 
26. 
27. 
28. 

28. 

29. 

30. 

31. 

32. 

33. 

34. 
35. 
36. 

37. 


Ottawa 
Ottawa 
I  Ottawa 
Ottawa 
Ottawa 
Ottawa 
Ottawa 
Ottawa 
i  Htawa 
Standardised 
Stan  darned 
.Ottawa 
II.   S.   Sjghed 
:fJ.   s.   s 


How  sold 


shed 
shed 
shed 
shed 
shed 
shed 
shed 
shed 
shed 


Lgnesi 

de 

de 

de 

shed 

died 


III.    S.    S 
Benson - 
I  I.enson- 
j  Benson - 
Wed  r  on 
I  Wedron 
>  Wedron  khed 
!  Wedron  Jhed 
Wedron  ift 
Old  Mol« 

Twin  '. 
National|e 
I  National  ie 
jBellrose  \e 
llllinois  ^\e 
|Standar<ift 
iHigby-R 
j  (Higb3le 
Higby-Re 

(Higb3le 
!Higby-Rie 
!  (Higb3[e 
!Higby-Rfe 
1  (Higb5[e 
Higby-Re 
i  (Higbye 
Higby-R? 
!  (Higbj . 
IfJtica  Fif 
(Federal  * 
Federal  ~  = 
;Higb3^-Ee  8 

mSy^r  ^ 

I      <E.  J,  jg 


shed 
14-inch 


bed 


a  Calculated 


ier- 

me, 

nay 

Table  1( 

Kind 

tive 

of 
sample 

On  20 

On  28 

On  35 

Oh  48 

the 

ient 

). . 

Face 

2.2 

23.6 

35.2 

>ve- 

).. 

Face 

1.2 

12.0 

28.9 

tify 

Face 

m , 

2.8 

31.2 

36.5 

Face 

.1 

2.1 

21.0 

28.6 

few 

Face 

.05 

3.8 

27.9 

38.8 

'i) 

Face 

.1 

9.3 

'48.1 

27.9 

ans 

•  i) 

Plant  run 

.3 

12.5 

43.0 

23.6 

>. . . 

Face 

.2 

7.1 

38.4 

27.9 

rhe 

Face 

Trace 

6.0 

38.0 

29.8 

Face 

.3 

9.3 

38.5 

25.9 

io\- 

Face 

.7 

13.7 

41.0 

22.0 

35' 

i  is 

Face 

.0 

2.2 

19.3 

34.7 

Face 

.0 

2.6 

20.9 

30.6 

Bed 

.0 

0.3 

5.4 

21.6 

Bed 

.0 

.9 

11.7 

31.8 

as 

Plant  run 

.1 

6.0 

41.3 

31.7 

Face 

.  . 

.8 

6.7 

27.8 

ins, 

.... 

Face  (Chip) 

.1 

1.9 

8.5 

20.2 

the 

Plant  run 

,  m 

.4 

4.7 

16.3 

10," 

uff) 

Face  (Chip) 

.. 

.6 

4.2 

16.8 

ven 

N., 

Face  (Chip) 

1.5 

7.4 

19.0 

For 

'  ib' 

Face  (Chip) 

'.1 

3.2 

16.9 

29.7 

for 

'  ii' 

Face  (Chip) 

.0 

1.1 

5.8 

17.0 

tied 

'  10 
i).. 

Face  (Chip) 

2.7 

17.5 

34.2 

>ne, 

iond 

^est 

.... 

Chip 

.1 

3.1 

11.0 

22.5 

an 

oun 

Face  (Chip) 

, . 

.7 

4.4 

23.6 

.1  a 

reran 

Face  (Chip) 

.  . 

.4 

2.3 

13.8 

ads 

one,! 

7    if 

....  Face  (Chip) 

.  . 

.3 

13.5 

N.J 

ieir 

one) 

.1 

4.5 

10.2 

9.2 

.... 

t 

.4 

3.9 

15.2 

.'  28, i 

■" 

.9 

10.8 

30.0 

-tal 

long 

.2 

13.1 

30.1 

27.3 

sed 

t!  ii 

md 

.2 

4.3 

15.5 

25.6 

ite)  .* 

.0 

.3 

3.1 

15.0 

out 

>wn) 

.0 

.4 

3.5 

14.8 

1  N., 

ess 

jperj 

i 

.2 

3.7 

1    13.9 

urn 

stead  of  3  sieves 

(See  pp 

.  157-1E 

8). 

md 

rhe 

md 

bo° 

s. 


5  Idem,    p.    215. 


148 


tion 

£he  ) — Continued 


°i   {            Per  cent  by  weight 

Fineness 
modulus  a 

Through 

How  sold 

On  G5 

On  100 

On  150 

Oh  200 

On  270  Wi 

Total 

Clay 

acc( 

sam  16-5 

13.9 

4.9 

1.9 

.8 

.8 

99.8 

1.0 

2.53 

Crude 

disc  20-2 
uibL  13  4 

19.6 

10.9 

4.1 

1.5 

1.5 

99.9 

2.3 

2.22 

Crude 

9.6 

3.6 

1.6 

.6 

.6 

99.9 

1.2 

2.65 

Crude 

qua  III 

14.6 

10.4 

5.6 

2.0 

1.2 

99.9 

2.8 

2.31 

Crude 

10.1 

1.8 

.4 

.05 

.3 

99.9 

1.1 

2.71 

Crude 

det<  ii:8 

4.5 

0.6 

.2 

.1 

.2 

100.0 

1.22 

2.93 

Washed 

7.6 

1.5 

.4 

.1 

.1 

100.1 

. . 

2.90 

Washed 

fact  14-6 

10.2 

1.9 

.7 

.5 

.6 

100.1 

1.1 

2.74 

Crude 

15.0 

8.1 

1.7 

.8 

-4 

.2 

100.0 

1.7 

2.76 

Crude 

11.6 

7.5 

3.r> 

2.0 

.8 

.6 

100.0 

1.5 

2.75 

Crude 

10.6 

7.2 

2.0 

1.1 

.6 

■f> 

100.0 

2.3 

2.87 

Crude 

pp. 

1  x        20.1 

17.1 

4.0 

1.2 

.7 

.6 

99.9 

2.50 

can   17.7 

17.5 

6.2 

3.2 

7 

.4 

99.8 

2*6 

2.45 

Washed 

21.3 

35.4 

9.4 

S.4 

l'.7 

1.7 

100.2 

2.9 

2.08 

Washed 

on  1    22.2 

23.4 

6.3 

2.1 

.9 

.6 

99.9 

2.05 

2.34 

Washed 

'    11.8 

6.9 

1.4 

.5 

2 

.1 

100.0 

2.83 

Washed 

28.4 

27.5 

6.3 

.   1.8 

.4     i 

.3 

100.0 

1.33 

2.27 

Washed 

22.2 

37.6 

7.9 

1.1 

.2    - 

.1 

99.8 

2.23 

25.9 

43.3 

7.8 

1.2 

.1 

.2 

99.9 

2.12 

Washed 

26.8 

38.1 

9.8 

2.6 

.6 

.6 

100.1 

.83 

2.08 

23.9 

33.6 

10.0 

3.3 

.8 

.5 

100.0 

2.14 

26.4 

19.5 

3.1 

.7 

.1 

.4 

100.1 

2.49 

san 

ha^  22'4 

36.1 

12.4 

3.6 

.8 

.8 

100.0 

2.06 

the   254 

16.8 

2.4 

.5 

.1 

.3 

99.9 

2.53 

are   27  8 

28.9 

5.0 

1.1 

.2 

.2 

99.9 

2.33 

san    38.4 

27.9 

4.0 

.7 

.1 

.1 

99.9 

2.24 

^    33.4 

41.2 

6.5 

1.9 

.4 

.1 

100.0 

2.08 

ind 

pre  39.1 

36.3 

7.0 

2.4 

•8 

.6 

100.0 

2.02 

me     3.9 

7.4 

19.6 

28.5 

12.5 

4.0 

99.9 

5.5 

1.47 

25.5 

34.8 

11.7 

4.5 

1.5 

2.5 

100.0 

1.96 

det   24.7 

23.6 

6.7 

1.9 

.7 

.6 

99.9 

2.31 

18.0 

9.7 

1.2 

_2 

.1 

.1 

100.0 

s 

2.82 

am 

'     22.4 

26.0 

5.1 

■  .7 

.1 

.1 

100.0 

, 

2.44 

an*  27.2 

41.3 

10.3 

1.9 

.6 

.3 

100.0 

.'. 

2.05 

bee   2G-6 

39.8 

J  0.7 

2.7 

.7 

.9 

100.1 

2.03 

Pr(     WA 

42.8 

7.3 

2.0 

.5 

.2 

100.0 

2.07 

! 

me 
the 
the 

]  >al 


TESTS    FOR    ANGULARITY  149 

of  the  same  mass  if  the  former  rolled  on  its  shortest  circumference.  Further- 
more, unless  the  sand  grains  are  introduced  on  to  the  incline  one  at  a  time, 
there  may  be  interference,  crowding,  and  pushing  of  the  grains  which  may 
complicate  or  partly  invalidate  the  results. 

In  an  endeavor  to  find  some  mechanical  means  of  determining  relative 
roundness  or  angularity  which  would  avoid  the  foregoing  complications,  the 
author  has  used  the  following  method  with  considerable  success.  Sufficient 
work  has  not  yet  been  done  to  make  the  procedure  perfect  and  many  improve- 
ments may  be  made  and  errors  eliminated,  but  the  results  seem  to  justify 
description  of  the  method  at  the  present  time.  The  method  involves  a  few 
simple  facts  which  are  by  no  means  new,  and  consists  essentially  of  a  means 
of  determining  the  minimum  porosity  of  sand  obtainable  by  compacting.  The 
most  angular  grain  possible  is  defined  as  the  grain  having  the  minimum  vol- 
ume and  maximum  surface  area ;  and  conversely  the  most  rounded  grain  is 
one  having  the  maximum  volume  and  the  minimum  surface  area. 

When  perfectly  spherical  grains  of  the  same  diameter  are  arranged  as 
compactly  as  possible,  that  is  so  that  each  grain  touches  twelve  other  grains, 
the  pore  space  will  be  25.95  per  cent.4  The  port  space  is  independent  of  the 
diameter  of  the  sand  grains  provided  that  they  are  all  the  same  in  a  given 
sample.  Further  King  says  of  samples  compacted  by  gentle  jarring:  "For 
simple  sands  with  angular  grains  the  pore  space  is  much  larger  than  it  is  for 
the  rounded  sands  of  the  same  sizes  of  grains,  and  in  the  case  of  the  crushed 
glass,  whose  grains  are  more  angular  than  those  of  the  crushed  limestone, 
which  have  a  tendency  to  be  cuboidal  in  form,  the  pore  space  is  the  largest 
of  all."5  It  follows  then  that  under  conditions  of  maximum  compaction  an 
angular  sand  of  a  given  uniform  size  will  have  a  greater  porosity  than  a 
rounded  sand  of  the  same  size  of  grain.  It  is  possible,  then,  to  compare  sands 
as  to  their  angularity  or  lack  of  angularity  on  the  basis  of  their  porosity  if 
sand  grains  of  the  same  size  are  used  and  if  they  can  be  made  to  assume  their 
arrangement  of  minimum  porosity  similarly  by  mechanical  means. 

The  apparatus  used  to  produce  minimum  porosity  consisted  of  a  metal 
tube  1%  inches  in  diameter  working  in  two  guide  sleeves,  which  was  raised 
about  half  an  inch  from  below  by  a  plunger  operating  on  an  eccentric  and 
allowed  to  drop.  The  raising  and  dropping  was  repeated  at  a  rate  of  about 
100  times  a  minute.  The  cylinder  struck  on  a  piece  of  felt  of  such  thickness 
as  to  produce  as  nearly  as  possible  a  "dead"  fall,  thus  reducing  to  a  minimum 
the  amount  of  rebound  imparted  to  the  sand  grains  in  the  cylinder  and 
directing  the  force  of  the  fall  towards  their  downward  concentration.  The 
machine  was  motor  driven  at  a  constant  speed. 

The  modus  operandi  was  as  follows :  About  60  cubic  centimeters  of  sand 
carefully  screened  to  a  given  sieve  size  on  a  Rotap  shaker  and  dried  at  100° 

4  King,   F.   H.,   Principles  and   conditions  of  the   movements  of  ground  water:     U.    S. 
Geol.   Survey  Nineteenth  Ann.  Rept.,  pt.   2,   p.   207,   1899. 
5  Idem,    p.    215. 


150  THE    ST.    PETER    SANDSTONE    OF    ILLINOIS 

C.  was  placed  in  the  cylinder,  and  the  machine  was  started.  After  a  few 
moments  the  machine  was  stopped,  a  graduated  rod  was  inserted  in  the 
cylinder,  and  the  volume  of  the  sand  was  measured.  The  machine  was  then 
restarted  and  the  operation  was  continued  until  the  volume  of  sand  in  the 
cylinder  could  be  reduced  no  further.  This  volume  was  taken  to  represent 
the  volume  of  the  sand  grains  themselves  plus  the  volume  of  the  voids  under 
conditions  of  maximum  compaction  and  minimum  porosity.  The  volume  of 
the  sand  grains  was  determined  by  pouring  the  sand  into  a  funnel  with  a 
small  discharge  aperature  which  allowed  it  to  run  slowly  into  a  graduate 
partly  filled  with  water,  and  then  noting  the  amount  of  water  displaced.  The 
small  opening  of  the  funnel  minimized  the  likelihood  of  the  inclusion  of  any 
large  volume  of  air.     The  per  cent  of  porosity  of  the  sand  was  determined 

as  follows:  (c— ^xioo 

P= 

where  C 

C  is  the  volume  of  the  sand  and  voids  measured  in  the  cylinder 

V  is  the  actual  volume  of  the  sand  grains  as  calculated  from  the  amount  of  water 

displaced  in  the  graduate 
P  is  the  per  cent  porosity,  with  maximum  compaction. 

With  the  apparatus  described,  tests  wlsj:e  run  on  ten  samples  of  sand, 
nine  of  them  from  the  St.  Peter  and  one  from  the  cypress  sandstone  of  Mis- 
sissippian  age,  for  purposes  of  comparison.  The  analyses  were  run  in  tripli- 
cate and  the  results  were  in  general  sufficiently  close  to  make  additional  tests 
unnecessary.  Table  12  gives  the  per  cent  of  porosity  as  determined  by  aver- 
aging the  results  of  the  three  tests.  The  relative  angularity  figure  for  the 
sands  has  been  determined  by  dividing  25.95,  the  theoretical  minimum 
porosity  for  spherical  grains,  by  the  porosity  of  the  sample.  The  nearer  the 
figure  is  to  1.0,  the  rounder  the  sand. 

RESULTS  OF  TESTS 

The  results  of  the  tests  are  shown  in  Table  12: 

The  table  shows  that  the  St.  Peter  varies  areally  as  to  angularity  and  that 
the  sand  of  the  Ottawa-Utica  district  is  slightly  more  angular  In  general  than 
the  St.  Peter  elsewhere  in  Illinois.  The  Cypress  sand  is  included  simply  for 
contrast  and  to  show  the  results  from  artificially  crushed  and  very  angular 
sand.  The  high  angularity  shown  in  the  sand  retained  on  the  35-mesh  sieve 
is  clue  to  the  fact  that  the  grains  consisted  of  aggregates  of  quartz  grains  and 
therefore  had  a  Very  irregular  shape  with  many  re-entrant  angles. 

As  a  check  on  this  procedure  and  its  value,  photographs  were  taken  of 
the  different  grades  ;oi  -sarid  of  six  of  the  above  samples.  These  were  sub- 
mitted to  a  number  of  individuals  to  be  arranged  in  order  according  to  the 
roundness  of  the  grains.  Exact  coincidence  with  the  order  suggested  from 
the  above  results  was  rarely  obtained  but  the  average  of  the  judgments  seems 
to  justify  fully  the  results  described. 


TESTS    FOR    ANGULARITY 


151 


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Ottawa   Silica   Com 
Wedron  Silica  Com 

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Standard    Silica    Co 
I  Plant  No    -n 

Outcrop   at  Troy  G 
Ballou  White  Sand 
National    Silica    Co 
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152 


THE    ST.    PETER   SANDSTONE    OF   ILLINOIS 


Tests  to  Determine  the  Number  of  Grains  in  a 
Unit  Weight  of  Sand 

method  of  procedure 

Inasmuch  as  it  is  often  of  interest  from  an  economic  and  scientific  stand- 
point to  know  the  number  of  grains  of  a  given  size  in  a  particular  sample, 
tests  were  made  to  give  an  approximate  idea  of  the  composition  of  the  St. 
Peter  sands  by  number  of  grains.  These  tests  consisted  of  a  determination 
of  the  average  number  of  grains  in  a  gram  of  sand  of  a  given  size. 

From  a  sample  of  very  carefully  washed  and  sieved  sand  of  a  given  size  a 
number  of  grains  were  counted  out  and  weighed.  From  this  weight  the 
weight  of  a  single  grain  was  calculated  and  also  the  number  of  grains  per 
gram.  This  was  done  for  the  various  grades  of  sand  of  six  different  samples 
selected  so  as  to  be  geographically  representative  of  the  St.  Peter.  From  the 
average  number  of  grains  per  gram  obtained  from  these  data,  the  analyses  by 
weight  were  recalculated  to  per  cent  by  number  and  are  recorded  in  Table  11. 


West  face 
28435  +48 


-1-65 


100 


150 


■200 


+  270 


Pan 


i    i 


South  face 


East  face 


niijijijijijii 


Fig.  41.  Graph  showing  the  composition  of  the  samples  from  the  quarry  of  the 
Ottawa  Silica  Company  in  per  cent  by  number  of  grains.  (Compare  with 
figs.  13   and  14,  pp.  43,  44.) 

RESULTS   OF   TESTS 

Table  13  shows  the  results  of  the  experimental  work. 

Figure  41  shows  the  percentage  composition  by  number  of  grains  for  the 
face  samples  taken  in  different  parts  of  the  quarry  of  the  Ottawa  Silica 
Company.  Compared  with  the  graphs  of  figures  13  and  14,  the  striking  dif- 
ference is  in  the  much  larger  per  cents  of  the  materials  below  100  mesh.  It  is 
also  of  interest  that  the  per  cents  retained  on  the  various  sieves  show  much 
less  variation  between  maximum  and  minimum  amounts  than  do  the  per 
cents  by  weight. 

In  figure  42  the  analyses  of  bed  samples  in  per  cent  by  number  of  grains 
are  shown  for  two  quarries.  The  greater  similarity  of  these  graphs  as  com- 
pared with  graphs  based  upon  the  per  cent  by  weight  (fig.  12)  is  worthy 
of  note. 


TESTS    FOR    NUMBER    OF    GRAINS 


15: 


cs: 


Number 
of  grains 
per  gram 
used  for 
computing 

per  cent 
by   number 

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number 

of  grains 

per  gram 



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154 


THE    ST.    PETER   SANDSTONE    OF    ILLINOIS 

Chemical  Analyses 


In  view  of  the  fact  that  repeated  analyses  of  the  St.  Peter  sand  have 
shown  it  to  contain  over  97  per  cent  of  silica  in  the  crude  state,  and  over  99 
per  cent  when  washed,  no  additional  analyses  were  made.     Data  as  to  the 


Table  14. 

— Chemical  analyses 

of -St.  Peter  sanda 

Company 

Si02 

MgO 

CaO 

Fe203 

A1203 

Total 

Authority 

Ottawa    Silica 

99.45 
99.89 
99.89 

99.576 
99.82 

Trace 
0.01 
0.01 

0.002 

0.13 
0.00 
0.00 

0.0197 
0.13 

0. 
Trace 

.0903 
0. 

30 
.051 
.051 

.283 
05 

99.88 
99.95 
99.95 

99.97 
99.99 

Prof.   R.    E.   Lyons, 
Indiana   University 

R.  W.   Hunt  &  Co., 
Chicago 

Cary   &    Moore, 
Chicago 

Operators  of  Quarry 
Prof.  R.  E.  Lyons, 
Indiana    University 

United  States 

Silica    Company 

Wedron  Silica 

Company 

Higby-Reynolds 

Silica    Company 

(Reynolds  quarry) 
Ottawa   Silica 

a  U  S.   Geol.   Surve 

y,   Min< 

sral  Re 

sources 

1911, 

Pt.    2,    J 

3p.    624 

and   630,    1912. 

Ottawa  Silica  Co. 
28+35    +48     +65 


+  100 


■I'lWrn 

ilM1 


150 


200 


+  270 


III    l|l|l| 
I    I    I    I    I 


Benson  -  Richards  Sand  Co. 


■ 


llllllllll 
1 1 1 1 1 


Fig.  42.  Graphs  showing  the  analyses  by  number  of  grains  of  bed  samples  from 
the  quarries  of  the  Ottawa  Silica  Company  and  the  Benson-Richards  Sand 
Company.     Sample  numbers  are  indicated  at  the  right  of  the  graphs. 

amount  and  chemical  composition  of  the  clay  of  the  St.  Peter  and  as  to  the 
amount  of  iron  present  are  given  in  Chapter  II.  The  analyses  in  Table  14 
are  typical. 


MODES    OF    EXPRESSING   TEXTURE 


155 


Modes  of  Expressing  Texture  from  Mechanical  Analyses 

effective  size 

The  effective  size  of  a  sand  is  most  commonly  used  with  reference  to 
hlter  sand  and  is  the  measure  of  the  opening,  expressed  in  millimeters,  which 
will  pass  10  per  cent  of  the  average  sample  of  sand.  The  nearer  the  effective 
size  is  to  1.0  the  coarser  the  sand.  The  effective  sizes  of  the  face  samples 
from  the  plants  producing  washed  sand  are  shown  in  Table  15.  Inasmuch 
as  the  sand  sold  as  filter  sand  is  usually  a  screened  product  this  table  does  not 
show  the  character  of  the  prepared  sand  but  does  indicate  the  character  of 
the  sand  as  found  in  nature  and  suggests  what  exposures  are  likely  to  furnish 
the  highest  per  cent  of  sand  suitable  for  filter  sand. 


UNIFORMITY  COEFFICIENT 

The  uniformity  coefficient  of  a  sample  of  sand  is  obtained  by  dividing 
the  size  of  opening  expressed  in  millimeters  which  will  just  pass  60  per  cent 
of  the  sand  by  the  effective  size.  The  uniformity  coefficient  is  intended  to 
indicate  the  uniformity  of  the  sand  or  the  variation  in  the  50  per  cent  of  sand 
lying  between  the  finest  10  per  cent  and  the  coarsest  40  per  cent.  The  closer 
the  uniformity  coefficient  is  to  zero  the  more  uniform  the  sand. 

Table  15. — The  effective  size  and  uniformity  coefficient  of  St.  Peter  sand  front  quarries 
of  plants  producing  washed  sand 


Sample 
No. 

Company 

Effective 
size 

Uniformity 
coefficient 

1 
2 
3 
7 

Ottawa  Silica  Company  (plant  A,  west  face) 

Ottawa  Silica  Company   (plant  A,  south  face)... 
Ottawa   Silica   Company    (plant  A,   east  face)... 
Ottawa    Silica    Company    (plant   B) 

0.208 
0.295 
0.295 
0.237 
0.188 
0.147 
0.167 

0.167 
0.255 
0.138 
0.152 

2.20 
1.66 
1.70 
2.03 

9 

Standard   Silica  Company   (plant  No.  2) 

2.06 

13 

United  States  Silica  Company 

2.62 

18 

Wedron  Silica   Company 

1  88 

36 

Higby-Reynolds    Silica    Company 

2  10 

43 

Standard  Silica  Company   (plant  No.   1) 

1.90 

47 

Ballou  White  Sand   Company 

2.48 

51 

National    Silica   Company 

1.82 

FINENESS 

The  difficulty  of  readily  comparing  the  sieve  analyses  of  different  sands 
because  of  the  number  of  components  making  up  such  analyses  has  led  to  the 
suggestion  of  various  methods  of  expressing  the  fineness  of  a  sand  by  a  single 
figure.  Different  users  of  sand  have  developed  different  means  of  arriving  at 
this  unit  of  expression  and  these  methods  are  described  in  the  following 
paragraphs. 


156  THE    ST.    PETER    SANDSTONE    OF   ILLINOIS 

PER   CENT  OF  FINENESS6 

The  per  cent  of  fineness  is  determined  by  adding  the  per  cents  of  sand 

passing  the  sieves  of  a  given  set  and  dividing  the  number  thus  obtained  by  the 

number  of  sieves  used.     The  per  cent  of  fineness  figures  of  a  number  of 

samples  of  sand  are  comparable  only  if  they  have  been  sieved  with  identical 

sieves.     The    following   example    shows    how    the    per   cent    of    fineness    is 

determined : 

Mesh  of  sieve  Per  cent  passing 

20 99.5 

28 94.5 

35 59.1 

48 29.3 

65 15.4 

100 5.2 

150 2.5 

200 1.2 

270 0.6 

9)307.3 

34.1    (per  cent  of 
fineness) 
AVERAGE    FINENESS     fsCRANTON    METHOD ) 

The  International  Correspondence  Schools  of   Scranton  recommend  in 

their  publications  on  molding  sand  that  the  constitution  of  sands  be  expressed 

by  the  average  fineness  figure.    A  set  of  sieves  are  used  of  mesh  indicated  in 

the  example  given  below.     The  fineness  figure  is  determined  by  multiplying 

the  weight  of  the  sand  passing  each  sieve  by  the  number  of  mesh  of  the  sieve 

and  dividing  the  total  of  all  the  sieves  by  100.   The  60-mesh  sieve  is  credited 

with  any  loss  occurring  during  the  sieving  operation  and  the  sand  not  passing 

the  20-mesh  sieve  is  credited  to  a   1-mesh  sieve.     The  following  example 

illustrates  this  method  more  concretely: 

Weight  of  sand  passing  one 
sieve     and     retained     on    the 
Mesh   of   sieve                                next 

100                          x                         5.2  520.0 

80                          x                          5.0  400.0 

60                          x                       10.0  600.0 

40                          x                       20.0  800.0 

20                           x                        59.2  11-84.0 

1                          x                         0.5  0.5 

60                          x                         0.1    (Loss)  6.0 

100)3510.5 

35.1 
Average  fineness 

The  average  fineness  figure  is  sometimes  spoken  of  in  commercial  par- 
lance as  the  fineness  number. 

6  Kummel,    H.     B.,    and    Hamilton,    S.    H..    A    report    upon    some    molding    sands    of 
New  Jersey:     Oeol.  Survey  of  New  Jersey  Ann.  Rept.  for  1904,  pp.  208-200,  1905. 


MODES    OF    EXPRESSING    TEXTURE 


157 


This  method  serves  as  a  basis  for  comparing  sand  but  is  open  to  the 
objection  that  it  is  possible  by  selecting  analyses  to  obtain  the  same  fineness 
figure  from  sands  of  different  sieve  analyses. 

AVERAGE   GRAIN    SIZE7 

The  average  grain  size  is  a  means  of  expressing  the  size  of  the  average 
grain  of  a  sample  of  sand.  It  is  determined  by  calculating  the  average  size 
of  each  mesh  of  a  sieve  of  a  given  number  of  mesh  per  linear  inch  and  mul- 
tiplying it  by  the  amount  of  sand  retained  on  the  given  sieve  expressed  as 
fractions  of  unity.  The  following  example  illustrates  the  calculations 
involved : 


Sieve    analysis 


Calculations 
for    average    grain    size 


Mesh 

Per  cent 

Fraction  of 
unity 

Aver 

age  screen  size" 
Inches 

Product  of  columns 
3    and  4 

20 

8.2 

.082 

X 

.066 

.00541 

40 

43.2 

.432 

X 

.037 

.01600 

60 

24.0 

.240 

X 

.019 

.00456 

80 

12.0 

.120 

X 

.013 

.00156 

100 

10.1 

.101 

X 

.011 

.00111 

250 

1.8 

.018 

X 

.007 

.00013 

Pan 

0.7 

.007 

x 

.002 

.00001 

100.0 

Total        .02878 

Average  grain  size 

aThese  average  screen  sizes  are  those   suggested  by  Ries  and  Rosen. 

A  sand  having  the  average  grain  size  indicated  above  would  pass  a 
20-mesh  sieve  (.0328-inch  openings)  and  be  retained  on  a  24-mesh  sieve 
( .0276-inch  openings  ) . 

The  facts  that  an  average  screen  size  must  be  calculated  and  that  the 
size  of  the  sand  retained  on  any  sieve  varies  between  the  sizes  of  the  mesh  of 
the  retaining  sieve  and  of  the  mesh  of  the  sieve  through  which  it  passes  on  to 
the  retaining  sieve,  are  the  chief  sources  of  error  in  this  method. 


FINENESS    MODULUS 

The  most  recent  work  in  determining  a  single  figure  which  will  give  the 
fineness  of  a  sand  has  been  done  by  Abrams8  who  devised  the  fineness 
modulus. 

The  fineness  modulus  of  an  aggregate  is  defined  as  the  sum  of  the 
percentages  given  by  the  sieve  analysis  either  by  weight  or  by  volume,  divided 


7  Ries,    H.    and    Rosen,    J.    A.,    Foundry   sands    of   Michigan:      Michigan    Geol.    Survev 
Ann.    Rept.    for   1907,   pp.    50-51,    190S. 

8  Abrams,     D.     A  ,     Design     of    concrete     mixtures:      Structural     Materials     Research 
Laboratory    Lewis    Institute    Bull.    1,    pp.    5-7,    Chicago,    1924. 


158 


THE    ST.    PETER   SANDSTONE    OF   ILLINOIS 


by  100.  It  is  recommended  that  sieves  be  used  each  of  which  has  a  clear 
opening  double  that  of  the  preceding-  one.  The  following  example  shows 
how  the  fineness  modulus  is  calculated : 


Mesh  of  sieve 

28 

48 

100 

200« 


Per  cent  retained 

5.5 

70.7 

94.8 

98.8 


100)269.8 

2.69  Fineness  modulus 

The  Number  of  Grains  as  a  Measure  of  Fineness 

It  may  be  said  in  general  that  the  larger  the  number  of  grains  in  100 
grams  of  sand  (Table  11,  analyses  by  number  of  grains)  the  finer  the  sand, 
and  vice  versa,  by  reason  of  the  fact  that  the  finer  grains  weigh  less  and 
therefore  are  more  numerous  in  a  100-gram  sample.  Although  this  method 
of  determining  a  single  figure  to  represent  a  sample  of  sand  is  open  to  some 
inaccuracies,  it  is  probably  of  as  much  interest  as  some  of  the  other  methods 
described  and  of  considerable  interest  as  supplementary  to  the  other  figures. 


Proposed  Classification  of  St.  Peter  Sand  on  the  Basis  of 
Fineness  Modulus 

Plotting  the  fineness  moduli  of  the  samples  of  St.  Peter  sand  gives  a 
graph  in  which  three  or  five  size  divisions  may  be  delineated.  The  following 
classification  of  the  St.  Peter  is  made  from  the  data  shown  by  the  graph : 

Coarse fineness  moduli  2.76  and  larger 

Medium fineness  moduli  above  2.30   and   below  2.76 

Fine fineness  moduli  2.30  and  smaller 

Plotting  the  moduli  of  the  samples  from  the  washed  and  crude  sand 
quarries  shows  the  following  relations : 

Per  cent  of  total  number  of  samples 


Total  number 
of    samples 

Fine 

Medium 

Coarse 

Crude   sand.... 

25 
21 

8 
14 

56 

33 

36 

Washed    sand 

53 

The  average  fineness  moduli  of  the  St.  Peter  sands  produced  in  Illinois  are 
as  follows : 


a  Abrams  does  not  mention  the  200  mesh  sieve  in  his  work  on  concrete  aggre- 
gates, hut  in  view  of  the  fact  that  the  St.  Peter,  sand  is  much  finer  than  concrete 
aggregates  it  has  seemed  worth  while  to  include  this  sieve  as  a  mean*  of  yielding 
more    exact    data   on    the   sand. 


GRAPHIC    REPRESENTATIONS    OF   SIEVE    ANALYSES  159 

Number    of  Fineness 

samples  modules 

28  All  washed  sand  2.60 

29  All    crude    sand    2.63 

15  Ottawa  district  washed  sand 2.85 

2  Millington   district   washed    sand 2.64 

2  Wedron    district   washed    sand 2.27 

2  Utica    district    washed    sand 2.29 

2  Oregon    district    washed    sand 2.20 

Graphic  Methods  of  Representing  Sieve  Analyses 

Sieve  analyses  may  be  represented  graphically  in  a  number  of  ways. 
These,  however,  may  be  generally  combined  into  two  groups :  ( 1 )  That  con- 
sisting- of  a  number  of  patterns  whose  total  length  or  area  represents  100  per 
cent  and  whose  individual  length  or  area  equals  the  per  cent  of  sand  retained 
on  a  given  sieve.  (2)  That  consisting  of  a  curve  plotted  on  rectangular 
coordinates.  The  vertical  axis  of  the  graph  is  commonly  the  per  cents  of  sand 
retained  and  the  horizontal  axis  the  sizes  of  the  sieve  openings  in  inches  or 
millimeters.  These  sizes  of  sieve  openings  may  be  plotted  as  arithmetical  dif- 
ferences or  as  the  logarithms  of  the  openings.  In  the  former  case  the  spaces 
on  the  horizontal  axis  of  the  graph  become  progressively  smaller  as  the  finer 
sieves  are  reached ;  in  the  latter  case  all  sieve  sizes  are  equally  spaced.  Figure 
43  shows  several  ways  of  representing  the  following  sieve  analysis : 

Sieve  Per  cent  retained  Cumulative  per  cent 

retained 

20 ; 2.0 2.0 

28 8.3 10.3 

35 42.0 52.3 

48 26.1 78.4 

65 9.4 87.8 

100 7.8 95.6 

150 2.3 97.9 

200 1 . 0 98.9 

270 0.5 99.5 

Pan 0.5 


100.0 


Each  of  the  diagrams  shown  in  figure  43  has  features  which  are  in  its 
favor.  Some  of  the  outstanding  ones  may  be  mentioned  briefly.  The  cumu- 
lative diagrams,  both  logarithmic  (A)  and  direct  (B),  permit  the  calculation 
of  the  amount  of  sand  retained  on  any  given  sieve,  whether  in  the  set  used 
for  the  analysis  or  not,  by  interpolation.  From  this  type  of  diagram  the 
effective  size  and  uniformity  coefficient  are  also  readily  calculated.  To  one 
familiar  with  sieve  analyses  represented  in  this  fashion  the  cumulative  dia- 
grams are  very  satisfactory.  They  lack,  however,  the  more  evident  propor- 
tional division  of  the  sizes  of  the  sands  and  percentages  of  each  shown  in  the 
other  diagrams.  Block  diagrams  C  and  D  are  similar ;  the  chief  difference  is 
that  D  requires  less  space  and  a  larger  number  of  diagrams  for  comparison 
can  be  drawn  in  a  given  space.     Block  diagram  E  permits  of  a  direct  reading 


160 


THE    ST.    PETER   SANDSTONE   OF    ILLINOIS 


100 

03 

o 

q 

OPENING 
in              - 

o           o 

N  INCH 

fM 

CO 

o 

q 

ES 
2) 

in 
o 
q 

o 
q 

o           c 
q           c 

90 

80 

70 

60 

"50 

°-40 

/ 

/ 

30 

/ 

/ 

20 

/ 

/ 

10 

/ 

/ 

MESHQ2 

y 

0           2 

8           3 

5            4 

8            6 

5           1C 

)0         IE 

>0         2( 

)0        27 

100 
90 
80 
70 

~60 
c 

0) 

°50 

^40 

30 

20 

10 

p«m0 


A  Cumulative  logarithmic  diagram 

MESH    MESH 


B  Cumulative  direct  diagram 


100 
C    Block  diagram  rj    Block  diagram  F    Circular  diagram 

Fig.  43.     Graphic  methods  of  representing  sieve  analyses. 


GRAPHIC    REPRESENTATIONS    OF   SIEVE    ANALYSES  161 

of  the  various  per  cents  of  the  component  parts  of  an  analysis  but  does  not 
show  the  relation  of  the  component  parts  to  the  entire  sample  or  100  per 
cent  as  readily  as  do  C  and  D.  It  also  requires  more  space  than  does  D  and  is 
therefore  somewhat  less  suited  for  visual  comparison.  Furthermore  it  is 
difficult  to  catch  the  difference  between  two  adjacent  bars  readily,  especially 
if  the  diagram  is  rather  small.  Circular  diagram  F  shows  very  readily  the 
relation  of  the  various  components  of  a  sieve  analysis  to  the  total  sample  of 
sand  but  is  space  consuming  and  not  particularly  suited  to  visual  comparison 
of  a  large  number  of  analyses. 


CHAPTER    VII— UNDEVELOPED    DEPOSITS    OF    ST.  PETER 
SANDSTONE  OF  POTENTIAL  COMMERCIAL  VALUE 

Introduction 

Considering  the  age  and  state  of  development  of  the  St.  Peter  sand 
industry  of  Illinois,  it  is  obvious  that  the  best  sites  for  commercial  operations 
are  being  developed  or  held  as  reserve  for  future  development.  Any  new  site 
to  be  capable  of  commercial  exploitation  must  be  one  from  which  sand  can  be 
produced  at  a  price  competitive  with  current  prices  of  sand  of  similar  grade 
and  character  already  in  the  market.  Whether  sand  can  be  produced  at  a 
competitive  price  from  a  given  deposit,  depends  on  a  number  of  variable 
factors,  some  of  which  are : — the  character  of  the  sand ;  natural  advantages 
which  make  quarrying  easy ;  the  amount  and  character  of  the  overburden  and 
the  ease  with  which  it  can  be  moved  and  disposed  of ;  the  skill  exercised  in 
quarrying ;  the  efficiency  of  the  quarrying  and  sand-preparing  equipment ;  the 
length  of  the  haul  from  the  quarry  to  the  railroad  cars ;  switching  charges  to 
trunk  railroad  lines ;  labor  costs  and  supply ;  and  the  volume  of  sand  which 
can  be  marketed.  Thus  at  times  of  low  prices  some  quarries  may  not  be  able 
to  produce  sand  at  a  profit  whereas  higher  prices  may  make  profitable  pro- 
duction possible  for  the  same  quarries. 

In  view  of  the  many  variables  involved  in  the  determination  of  what  a 
commercially  valuable  deposit  of  St.  Peter  sandstone  is,  it  is  proposed  to 
indicate  areas,  rather  than  specific  sites,  where  such  deposits  may  occur,  with 
any  pertinent  data  available  concerning  the  character  of  the  sandstone,  for 
the  guidance  of  those  interested.  Reference  should  also  be  made  to  Chapter 
II  for  details  of  the  distribution  and  character  of  the  St.  Peter  at  the  outcrops 
mentioned.  Some  of  the  deposits  mentioned  are  probably  not  commercially 
available  at  the  present  time  because  of  their  distance  from  a  railroad,  but  are 
potentially  valuable  as  a  future  source  of  supply. 

The  Rock  Terrace  of  Illinois  River  in  the  Vicinity  of  Ottawa 

The  rock  terrace  in  the  valley  of  Illinois  River  is  the  site  of  a  number 
of  washed  sand  quarries  and  most  of  the  available  acreage  close  to  transpor- 
tation either  is  not  on  the  market,  or  is  a  part  of  the  city  of  Ottawa.  How- 
ever, in  the  SW.  M  sec.  21  and  S.  *4  sec.  20,  T.  33  N.,  R.  3  E.,  there  is  a 
tract  probably  underlain  by  St.  Peter  sandstone  at  a  shallow  depth  in  places 
at  least.  The  sandstone  outcrops  in  the  NW.  J4  SW.  J/\  sec.  21  in  some 
abandoned  quarries.    In  the  vicinities  of  these  old  quarries  the  overburden  is 

162 


AREAS   OF   POTENTIAL   COMMERCIAL   VALUE  163 

largely  black  loam.  Elsewhere  it  is  probably  sand  and  gravel,  which  may 
possibly  be  worked  together  with  the  underlying  sandstone.  The  St.  Peter 
sand  is  probably  of  the  same  general  character  as  in  the  vicinity  of  Ottawa. 
The  chief  handicap  of  this  site  is  the  lack  of  transportation  close  by.  The 
nearest  railroad  connection  is  the  switch  of  the  South  Ottawa  Silica  Sand 
Company  about  two  miles  northeast. 

Buffalo  Rock 

There  are  already  a  number  of  quarries  in  the  northwest  side  of  Buffalo 
Rock.  The  east  end  of  the  Rock  is  the  site  of  a  sanitarium,  but  the  south  and 
a  part  of  the  southeast  sides  of  the  Rock  are  not  at  present  being  quarried. 
Some  abandoned  pits  occur  in  the  last  mentioned  tract,  but  there  is  still  a 
possibility  of  further  development.  The  overburden  is  similar  to  that  at  the 
quarries  of  the  Benson-Richards  Sand  Company,  Ottawa  Silica  Molding  Sand 
Company,  and  Buffalo  Rock  Silica  Company  which  are  located  in  Buffalo 
Rock.  The  sand  from  Buffalo  Rock  above  the  level  of  the  floor  of  Illinois 
Valley  is  probably  much  the  same  as  that  in  the  quarries  just  mentioned. 

There  is  a  possibility  that  on  the  west  end  of  Buffalo  Rock  the  sand- 
stone may  extend  as  a  sort  of  shelf  for  some  distance  west  from  the  foot  of 
the  Rock  under  a  cover  of  sand  and  gravel  capable  of  commercial  exploitation 
and  that  the  sandstone  is  of  such  purity  as  to  be  good  glass  sand. 

Transportation  at  Buffalo  Rock  could  be  furnished  by  the  Illinois  Trac- 
tion System. 

The  North  Bluff  of  Illinois  River  from  Ottawa  to  Utica 

The  North  bluff  of  Illinois  River  between  Ottawa  and  Utica  is  the  site 
of  the  majority  of  the  crude  sand  quarries  in  the  Ottawa-Utica  district.  How- 
ever, a  number  of  available  sites  still  remain  in  this  bluff  area.  The  principal 
problem  connected  with  the  development  of  these  sites  is  the  removal  and 
disposal  of  the  overburden.  As  has  been  previously  stated,  east  of  the  Higby 
Ravine  the  overburden  is  Pennsylvanian  shale,  clay  and  coal  and  some  glacial 
drift ;  west  of  Higby  Ravine  it  is  principally  glacial  drift.  The  character  of 
the  sand  in  this  bluff  and  the  quarries  already  operating  are  described  else- 
where in  this  bulletin. 

The  Illinois  River  Bluff  West  of  Utica 

West  of  Utica  the  Illinois  River  bluff  is  made  up  principally  of  Shakopee 
dolomite  with  a  capping  of  St.  Peter  sandstone.  The  best  site  for  a  quarry 
is  probably  about  an  eighth  of  a  mile  northeast  of  Split  Rock  in  sec.  13,  T. 
33  N.,  R.  1  E.,  where  the  steeply  dipping  beds  of  the  St.  Peter  underlie  a 
belt  about  an  eighth  of  a  mile  wide.     Back  from  the  bluff  the  area  widens  to 


164  THE    ST.    PETER    SANDSTONE    OF   ILLINOIS 

half  a  mile  or  more.1   The  overburden  is  glacial  drift.     The  sand  is  probably 
much  like  that  near  Utica. 

The  South  Bluff  of  Illinois  River 

From  Ottawa  west  to  Covel  Creek  the  south  bluff  of  Illinois  River  is 
composed  of  Pennsylvanian  beds.  West  of  Covel  Creek,  however,  the  St. 
Peter  rises  in  the  bluffs  and  forms  prominent  cliffs,  but  the  major  portion 
of  this  area  is  included  in  Starved  Rock  State  Park,  and  is  therefore  not 
available  for  commercial  exploitation.  The  portion  between  the  east  edge  of 
the  park  and  Covel  Creek  has  too  much  overburden  to  be  of  commercial  value 
except  for  mining. 

West  of  Starved  Rock  State  Park  in  sees.  19  and  20  T.  33  N.,  R.  2  E., 
is  a  strip  about  a  fourth  to  a  third  of  a  mile  wide  along  the  bluff  with  only  a 
moderate  cover,  which  might  be  commercially  exploited.  The  lack  of  trans- 
portation is  the  chief  handicap  of  this  site.  It  is  about  a  mile  and  a  quarter 
north  across  Illinois  River  to  the  Chicago,  Rock  Island  and  Pacific  Railway 
and  the  Illinois  Valley  Electric  Railroad. 

Vermilion  River 

The  outcrops  of  St.  Peter  along  Vermilion  River  are  not  extensive.  The 
overburden  is  glacial  drift  with  or  without  Pennsylvanian  beds,  or  Platteville- 
Galena  limestone.  Transportation  is  not  conveniently  near.  The  outcrops  are 
in  general  rather  low  and  it  is  probable  that  the  level  of  ground  water  in  the 
sandstone  would  prevent  very  deep  quarrying. 

Pecumsaugan  Creek 

In  sec.  6,  T.  33  N.,  R.  2  E.,  a  belt  about  a  half  mile  wide  along  the  west 
bank  of  Pecumsaugan  Creek  is  underlain  by  St.  Peter  sandstone  with  a 
moderate  cover.  This  site  is  handicapped  by  the  lack  of  convenient  trans- 
portation. 

Clark  Run 

Along  the  valley  of  Clark  Run  near  Utica  there  may  be  sites  where  the 
overburden  of  glacial  drift  is  thin  enough  to  permit  the  development  of  a 
quarry.  This  is  true  in  limited  areas  but  detailed  test  drilling  is  necessary  to 
determine  the  extent  of  such  a  condition.  A  gravity  system  for  running  cars 
from  the  quarry  to  the  railroad  at  Utica  could  perhaps  be  effected.  The  sand 
is  probably  like  that  in  the  Illinois  bluff  near  Utica. 


i  Gady,     G.     H.,     Geology    and    mineral    resources    of    the    Hennepin     and     La     Salle 
quadrangles:      Illinois    State    Geol.    Survey    Bull.    37,    PI.    I.    1!)19. 


AREAS    OF    POTENTIAL    COMMERCIAL    VALUE  165 

Fox  River 

The  outcrops  of  St.  Peter  along  Fox  River  are  limited  principally  to 
the  rock  terrace  in  the  valley  bottom.  At  the  edge  of  this  terrace  away  from 
the  river  the  overburden  consists  of  Pennsylvanian  strata  and  in  general  is 
too  heavy  to  be  moved.  In  places,  however,  the  rock  terrace  is  wide  enough 
to  permit  a  sizable  quarry.  The  overburden  is  principally  river  alluvium,  and 
is  commonly  3  to  6  feet  thick.  The  broadest  parts  of  the  rock  terrace  or  of 
the  Fox  valley  flats  are  in  sees.  3  and  21,  T.  34  N.,  R.  4  E. 

Test  drilling  is  advised  to  determine  the  general  character  of  the  over- 
burden and  St.  Peter  surface  in  this  area.  Inasmuch  as  the  terrace  was  once 
the  bed  of  Fox  River  its  surface  is  probably  uneven.  The  Chicago,  Burling- 
ton and  Ouincy  Railroad  is  located  along  the  west  side  of  the  valley. 

In  the  vicinity  of  Millington  it  is  possible  that  detailed  search  may  reveal 
additional  quarry  sites.  The  Chicago,  Burlington  and  Ouincy  Railroad  is  on 
the  east  side  of  the  river. 

The  Oregon-Dixon  Area 

There  are  many  good  sites  for  quarries  in  this  area  but  they  lack  trans- 
portation facilities.  The  country  is  for  the  most  part  dissected  and  quarries 
located  at  some  distance  from  a  railroad  are  therefore  not  generally  feasible. 
The  best  sites  are  between  the  quarry  of  the  National  Silica  Company  in  the 
center  of  sec.  8,  T.  23  N.,  R.  10  E.,  and  the  flat  of  Gale  Creek  about  a  mile 
east,  and  the  isolated  hill  in  the  E.  y2  sec.  10,  of  the  same  township.  Both 
of  these  sites  are  on  the  Chicago,  Burlington  and  Quincy  Railroad. 

The  first  site  will  require  considerable  exploratory  work  to  determine 
the  best  location  for  the  quarry.  The  overburden  is  glacial  drift  of  variable 
thickness  but  is  in  general  thin.     The  rock  surface  is  uneven. 

The  second  site  faces  Rock  River  on  the  west  and  is  practically  free 
from  overburden  on  that  side.  An  80-foot  face  of  sand  is  exposed.  The 
sand  is  very  yellow  and  streaked  with  iron  in  the  upper  25  feet.  Below  this 
it  is  less  yellow  and  freer  from  iron.  The  thickness  of  the  overburden  is 
difficult  to  determine  because  the  hill  is  wooded,  but  it  is  probably  between  5 
and  10  feet.    Sample  54  was  taken  from  the  exposure  along  the  river. 

Samples  55,  56,  57,  58  and  66  whose  locations  are  given  in  the  table  of 
fineness  tests  (Table  10)  were  taken  in  the  Oregon-Dixon  area  to  indicate 
the  general  character  of  the  sand  in  that  area.  A  brief  description  of  the 
locations  where  the  samples  were  obtained  follows : 

Sample  55 — railroad  cut  in  ridge. 

Sample  56 — 32  foot  exposure  of  upper  St.  Peter.  The  sandstone  is 
yellow  and  contains  irregular  iron  bands.  Locally  a  3-foot  cross-bedded 
layer  is  present.  Many  grains  of  sand  are  angular  probably  as  a  result  of 
secondarv  o-rowth. 


166  THE   ST.    PETER   SANDSTONE   OF   ILLINOIS 

Sample  57 — 60  foot  exposure  of  St.  Peter.  Some  of  the  beds  especially 
near  the  top  of  the  exposure  are  of  remarkably  even  grain.  In  general  the 
beds  are  thick  but  near  the  top  of  the  outcrop  y2  to  2-inch  beds  are  common. 
The  sandstone  is  not  notably  stained  by  iron. 

Sample  58 — 30  foot  exposure  of  sandstone  in  road  cut.  The  sandstone 
is  in  general  yellow,  especially  in  zones  12  to  24  inches  thick.  Bedding  is 
moderately  well  developed. 

Sample  66 — 30  foot  of  St.  Peter  in  road  cut;  probably  lower  St.  Peter. 
In  general  the  bedding  is  not  distinct.  Iron  is  present  as  yellow  horizontal 
bands. 

Brookville-Harper  Area 

Detailed  work  in  the  Brookville-Harper  area  in  Ogle  County  will  prob- 
ably reveal  suitable  sites  for  new  quarries.  The  country  is  rolling  and  consists 
largely  of  long  low  ridges  30  to  60  feet  high,  most  of  which  probably  have  a 
core  of  St.  Peter  sandstone.  The  overburden  consists  principally  of  2  to  5 
feet  of  loess,  underlain  by  1  foot  to  15  feet  of  glacial  drift.  Locally  limestone 
may  rest  on  the  sandstone  below  the  glacial  drift.  The  exposures  of  the 
St.  Peter  are  in  general  limited  to  a  few  feet  of  sandstone  which  is  badly 
yellowed  by  iron.  No  railroad  is  convenient  to  the  general  area  of  outcrop. 
Sample  70  comes  from  an  11-foot  exposure  of  sandstone  along  a  road. 

Calhoun  County 

The  outcrop  of  St.  Peter  sandstone  along  Mississippi  River  in  Calhoun 
County  between  Dogtown  and  West  Point  landings  is  capable  of  develop- 
ment only  so  as  to  employ  water  transportation.  There  are  no  railroad 
facilities.  Near  Dogtown  Landing  the  overburden  is  loess  from  20  to  40  feet 
thick.  Further  north  the  Joachim  limestone  rests  on  the  sandstone.  A  bluff 
of  about  80  feet  of  sandstone  is  exposed  as  a  nearly  sheer  cliff  along  the  river. 
The  character  of  the  sandstone  is  described  in  Chapter  II.  Sample  60  comes 
from  the  top  28  feet  and  sample  61  from  the  26  feet  of  sandstone  below  this. 
It  is  likely  that  detailed  exploratory  work  will  reveal  locations  where  the  over- 
burden is  sufficiently  thin  and  easy  to  remove  to  make  a  suitable  quarry  site. 
As  previously  mentioned,  the  sand  contains  calcareous  material  locally  and  is 
ferruginous  on  weathered  exposures. 


INDEX 


Abrasive,  ground  sand  as  an 101 

Absorbent,  sand  as  an 101 

Acknowledgements    13 

Adams  Co.,  St.  Peter  in 29,  50 

Agricultural  sands    101 

American     Foundrymen's     Associa- 
tion, method  for  testing  fineness 

by    146 

American  Silica  Sand  Co., 

description  of  plant 86 

fineness  tests  on  sand  from 148,  150 

iron  content  of  sand  from 55 

sieve  analyses  of  sand  from 45 

Analyses,  chemical,  of : 

clay  content  of  St.  Peter 51 

iron  content  of  St.  Peter 55 

St.  Peter  sand 154 

sand  for: 

brick  molding  106 

car  couplers    129 

glass  sand 120,121,122 

molding  bars 129 

pottery    133 

silica  mold  wash 114 

sodium  silicate   140 

Analyses,  mechanical    (seive)  : 

discussion   of    146-148 

by  number  of  grains  : 

discussion  of    49-50 

graphs  showing    152,  154 

tests  to  determine 152 

results  of  tests 152 

.    results  tabulated   153 

by  weight : 

graphic    methods    of    represent- 
ing    159-161 

graphs  showing  41,43,44,45,160 

tests  tabulated    148 

of  sand  for : 

asphaltic   flooring    104 

car  couplers    129 

concrete    110 

furnace  bottom   sand 117-118 

glass  sand   . . . 121 

molding  bars 129 

plasters     132 


PAGE 

pottery    133 

roofing    135 

sodium  silicate   140 

welding     142 

See  also  "Fineness"  and  "Texture." 

Anatase,  in  St.  Peter 59,  60,  61 

Angularity,  tests  for 148 

results  of,  table  12 151 

Annealing,  sand  for 101 

Area,  St.  Peter  near 20,  50 

Asbestos  shingles,  ground  sand  for.  101 

Asphalt  block  pavements 104 

Asphaltic  concrete  pavements 103 

Asphaltic  flooring,   sand  for 104 

Asphalt  pavements,  sand  for 101 

Average  fineness  of  St.  Peter  sand.  156 

Average  grain  size  of  St.  Peter  sand  157 

B 

Backing  sand,  see  "Molding  sand" 

Banding    sand    97,104 

Ballast  for  ships,  sand  as  a. ...... .     104 

Ballou  White  Sand  Co., 
analysis  of  clay  from  quarry  of..       51 

angularity  test  of  sand  from 151 

description  of  plant 76 

effective  size  of  sand  from 155 

fineness  tests  of  sand  from 148,150 

heavy    mineral    content    of    sand 

from    60 

sieve  analyses  of  sand  from 41,45 

uniformity     coefficient     of     sand 

from    155 

Basal  conglomerate  of  St.  Peter ...       27 

Bed  sample,  defined 144 

Bedding    and    cross-bedding    in    St. 

Peter     ....27,28 

Bedding  for  stock  cars,  sand  for...     105 
Bellrose  Sand  Co., 

angularity  test  of  sand  from.....     151 

description  of  plant....... 87 

fineness  tests  of  sand  from. ..  .148,  150 

iron  content  of  sand  from 55 

heavy    mineral    content    of    sand 

from    60 

sieve  analyses  of  sand  from 45,  153 


167 


168 


INDEX 


PAGE 

Benson-Richards  Sand  Co., 

description  of   plant 88 

fineness  tests  of  sand  from.  ...  148,  150 

iron  in  sand  from 55 

sieve  analyses  of  sand  from.  .41,  45,  154 
Bird  grit,  sec  "Poultry  grit" 

Blasting,  in  quarrying 66-67 

Bluff  quarries 63 

Borax  cement   109 

Brass   sand    105 

Brick  molding,  sand  for 105 

Brick,  sand  for  clay 105 

Brick,   sand  for  sand-lime 106 

Brick,  sand  for  silica 106 

Brick  pavements 107-108 

Biookville-Harper    area,    St.    Peter 
in : 

formations  overlying    22 

outcrops  of    14 

potential  value  of 166 

Buffalo  Rock: 

heavy     mineral     content     of     St. 

Peter  near  62 

location   of   quarry 93 

origin  of    , 16 

potentially  valuable  St.  Peter  near  163 
Buffalo  Rock  Silica  Co., 

description  of   plant 89 

Building  sand,  production  in  .1925..  11 

Burnishing   sand    108 

C 

Calhoun  Co., 

calcareous  beds  in  St.  Peter  in.  .  .  50 

Joachim  formation  in 22 

potentially  valuable  St.  Peter  in..  166 
St.   Peter  in : 

outcrops  of    14,  18 

ripple  marks  in 28,  33 

samples  from    44 

secondary   enlargement   of   sand 

grains   in    49 

sieve  analyses  of 45 

Cambrian  sandstones,  source  of   St. 

Peter  sand 30 

Cap-au-Gres  fault   18 

effects  of   25 

Capacity,  see  "Plants,  descriptions 

or 


PAGE 

Carbonaceous  bands  in  St.  Peter ...       37 
Carborundum,  sand  for  manufacture 

of 109 

Carroll    Co.,    formations    overlying 

St.    Peter  in 24 

Case  hardening  in  St.  Peter 18,  19 

Castle  Rock,  outcrop  of  St.  Peter..  16,  17 

Cements,    sand   for 109 

Chemical  analyses,  sec  "Analyses" 

Chemical  purposes,  sand  for 109 

Chert   conglomerate    20,  21 

Chicago,   St.   Peter  near 50 

Churn  drill,  study  of  records  of 19 

Chip  sample    144 

Clark  Run,  St.  Peter  along 164 

Clay  in  St.  Peter  : 

character  of    .  . 28 

chemical    analysis    of 51 

distribution  of    52 

origin  of   52-54 

Clay  pockets   37 

Clear  Creek,   St.   Peter  along 17 

Commonwealth  Silica  Co., 

description  of   plant 90 

fineness  tests  on  sand  from 148,  150 

worm  borings  in  quarry  of 36 

Compositional  features  of  St.  Peter  37-39 

Carbonaceous  bands    37 

clay  pockets    37 

interstitial  organic  material 37 

"magnesia"   beds    38 

siliceous   joint    fillings 39 

Conglomerate,  basal   St.   Peter 20,  21 

Coking  sand    109 

Core  sand,  see  "Molding  sand" 

Concrete,  sand  for 110 

Constants       for       Tyler       Standard 

Screen  Scale  Sieves 147 

Cook  Co.,  St.  Peter  in : 

basal  conglomerate  of 20 

calcareous  beds  in 50 

Council   Cave    35 

Covel  Creek,  St.  Peter  along 164 

Cross-bedding ; 

aqueous     27,  32 

eolian    27,33 

Crude  sand,  grades  produced 98 

production    of    84-85 

See  also  "Plants,  descriptions  of" 


169 


PAGE 

Cuspidors,   sand  for Ill 

Cutting  and  sawing"  sand 111-112 

Cypress    sand,    compared    with    St. 

Peter     150-151 

D 

Daysville,   St.  Peter  near 17 

Deer  Park,  St.  Peter  at 16 

DeKalb  Co.,  log  of  well  at  Malta..  24 

Dental   cements    109 

Dental  purposes,   sand  for 112 

Depth    to    sandstone,    determination 

of    25-26 

Dessication  cracks  in  St.  Peter ....  28 
Diagrammatic  flow  sheet  for  washed 

St.  Peter  sand 68 

Differential  weathering  of  St.  Peter  35 

Dispelling  fog,  sand  for 112 

Dixon,     formations     overlying     St. 

Peter    at 24 

Dogtown  Landing,  St.  Peter  near : 

outcrops  of    18 

ripple  marks  in 33 

potentially  valuable  166 

Dolomite  in   St.   Peter 50-51 

Drag-belt  elevator,  description  of..  71 

Draining  bins,  types  of 73 

Draining  washed   sand 73-74 

Driers,  types  of 74 

Drying  sand   74 

Dune-structure   27 

Dwight,  St.  Peter  near 20 

E 

Effective  size  of  St.  Peter  sand....  155 

table  15    155 

Elevating  sand  from  quarry 71 

Enameling,  sand  for 112 

Engine    sand    113 

Epidote  in  St.  Peter 59,60,61 

Equipment,  see  "Plants,  descriptions 

of" 

Erasers,   sand  for 113 

Explosives,   sand   for 113 

F 

Face  sample    144 

Facetted    pebbles 27 

Facing  sand    113 


PAGE 

Facing  tile  and  brick,  sand  for 114 

Federal   Silica  Mines, 

description  of   plant 90 

fineness  tests  of  sand  from.  ...  148,  150 

iron  in  sand  from 55 

Fertilizer  filler,  sand  as  a .  115 

Filler,  sand  as  a.  .  .  '. 115 

Filling  mines,  sand  for 115 

Filter   sand    115 

Fineness : 

average    (Scranton  method) 156 

discussion  of   155 

number  of  grains  as  measure  of . .  158 

per  cent  of 156 

tests,  by  number  of  grains 150 

tests,  by  weight 148 

Fineness  modulus  157-158 

Fineness  number    156 

See   also    "Analyses"    and   "Tex- 
ture" 

Fire  clay    22 

Fire  sand,  see  "Furnace  sand" 

Flat-bottomed   draining   bins 73 

Floor    plasters    131 

Floor  sand,  see  "Molding  sand" 
Flow    sheet    of    plant    of    National 

Silica  Co 82 

Flux  in  metallurgy,  sand  as  a 116 

Fox  River,  St.  Peter  along, 

commercial  development  of 12 

outcrops  of   14,  16,  165 

Franklin  Creek : 

New  Richmond  along 18 

St.  Peter  along 17,  33,  34 

Franklin  Grove,  St.  Peter  near 17,18 

French  sand H6 

Friction  sand    \\y 

Frosting  of  sand  grains 27,  46-47 

Furnace  and  fire  sand 117 

Fused  silica,  sand  for  making 117 


G 

Galena,  shale  below  St.  Peter  at 20 

Garnet  in  St.  Peter 59,  60,  61 

Genoa,     formations     overlying     St. 

Peter    at    24 

Geologic  history  of  St.  Peter 29 

Glacial  drift : 


170 


INDEX 


PAGE 

on  rock  terraces  near  Ottawa 14 

on  north  bluff  of  Illinois  River . .       16 

in  Oregon-Dixon  area. 17 

Glaciation 31 

Glass  sand 

description  of   97, 118-122 

production  in   1925 11 

quarry,  sun  cracks  in 36-37 

Glazes,  sand  for  making 122 

Glenwood  formation : 

deposition  of   30 

described  in  geologic  sections 22,  23 

overlying  sediments    17 

Glenwood-St.  Peter  contact 24 

Golf     tees,     traps,     hazzards     and 

greens,   sand  for 122 

"Gopher  holing"    66,  84 

Grab  sample 144 

Grades  of  sand  produced 96-98 

Grand  Detour,  St.  Peter  near 17,  36 

Grain  size : 

discussion  of    40-44 

average 156 

Graph  showing : 
amounts  and  values  of  St.  Peter 
sand    produced   in   Illinois    in 

1925  11 

geographic  variation  of  texture  of 

St.  Peter  sand 45 

graphic  representation  of  sieve  an- 
alyses         160 

sieve  analyses.  .39,  41,  43,  44,  45,  152,  154 

Grays  Lake,  St.  Peter  near 50 

Green  St.  Peter  sand,  iron  in 55 

Grinding  and  polishing  sand 123 

production  and  value  in  1925 11 

Grinding  wheels,  sand  for 123 

Ground  quartz,  value  in  1925 11 

Ground  silica  97-98 

Gypsum  plasters    131 

H 

Harper-Brookville  area,  see  "Brook- 
ville-Harper" 

Harvard,  St.  Peter  near 20 

Heavy  minerals  in  St.  Peter: 

discussion  of 59-62 

size  of    61 

table  showing  60 


PAGE 

Higby-Reynolds  Silica  Co., 

analysis  of  clay  from 51 

analysis  of  sand  from 154 

angularity  test  of  sand  from 151 

description  of  plant 78 

dessication  cracks  in  quarry  of . . .  36-37 
Higby  Canyon  quarry,  description 

of  plant    91 

iron  in  sand  from 55 

Reynolds  west  quarry,  description 

of  plant    92 

sieve  analyses  of  sand  from. ..  .45,  153 
uniformity     coefficient     of     sand 

from   155 

Horticultural  sands    123 

Hour-glass  sand   124 

Hydraulic  quarrying 67-69 

I 
Icy  streets  and  walks,  sand  for  use 

on    124 

Illinois,  calcareous  beds  in  St.  Peter 

in   ..'. 50 

Illinois,  rank  in  production  of  silica 

sand  in  1925 11 

Illinois  River  Bluff,  St.  Peter  in: 

outcrops  of   14 

potentially   valuable    163-164 

quarries  in 32,  37,  63 

Illinois  River : 

commercial    development    of     St. 

Peter  along  12 

outcrops  of  St.  Peter  along 16 

Illinois  Valley  Silica  Co., 

clay  pockets  in  quarry  of 37 

description  of  plant 92 

fineness  tests  of  sand  from. .  .  .148,  150 

iron  in  sand  from 55 

Interstitial    organic   material    in    St. 

Peter    37-38 

"Iron  bands"  defined 55 

Iron  content  of  St.  Peter 19,  54-59 

occurrence  55-57 

origin    57 

source  and  mode  of  accumulation.  57-59 


Joachim  formation,  above  St.  Peter.     166 
Joachim  time 30 


INDEX 


171 


PAGE 

Jo  Daviess  Co.,  St.  Peter  in 20 

Joliet,  relief  in  St.  Peter  at 25 

K 

Kankakee  Co.,  formations  overlying 

St.   Peter  in 24 

Kendall  Co.,  St.  Peter  in 16 

L 

Lake  Co.,  St.  Peter  in 20,29,50 

Lake  Forest,  St.  Peter  at 50 

Lakes  to  Gulf  waterway 12 

La  Salle  anticline, 

St.  Peter  absent  from  crest  of 16 

folding  of    30 

location   of    25 

La  Salle  area,  basal  St.  Peter  in...       21 

clay  content  of  St.  Peter  in 54 

erosion  of  post-St.  Peter  beds  in.       30 
section  of  Shakopee  formation  in.       19 
Lee  Co., 

New  Richmond  sandstone  in 18 

oolitic   chert    in 21 

St.  Peter  in 22,24 

Lime    plasters    131 

Limestone  in  St.  Peter .27,  29,  50-51 

Limonite  in  St.  Peter 59,  60,  61 

Lithology  of  St.  Peter 18-24 

Little  Rock,  St.  Peter  near 16 

Little    Vermilion    River,    St.    Peter 

near     16 

Livingston  Co.,  St.  Peter  in 20 

Loam,  see  "Molding  sand" 

M 

McHenry  Co.,  St.  Peter  in 20,  24 

"Magnesia"  beds  in  St.  Peter : 

analysis  of  sand  from 39 

description  of   38,  39,  50 

Malta,  log  of  well  at 24 

Manufacture  of  special  sands 74-76 

Marcasite  in  St.  Peter 59,60,61 

See  also  "Iron  content" 

Marine  fossils  in  St.  Peter 27 

Marine  origin  of  St.  Peter 26-28 

Matches,   sand  for 124 

Mechanical  analyses,  see  "Analyses" 

Mica  in  St.   Peter 61 

Millington,  St.  Peter  near: 

outcrops  of   14, 16 


potentially   valuable    165 

Mine-run  sand  97 

Miscellaneous     grades     of     washed 

sand     97 

Mississippi  River,  St.  Peter  along..       18 

Moisture  pad,  sand  as  a 125 

Molding  sand   125-130 

Molding  sand  quarries,  beds  in 32 

Morris-Kankakee  anticline  25 

Mortar  sand   130 

Mt.  Carmel  cemetery,  St.  Peter  at. 20,  50 
Mundelein,  St.  Peter  at 20,50 


N 

National  Plate  Glass  Co., 

description  of  plant 93 

fineness  tests  on  sand  from 148 

interstitial     organic     material     in 

quarry  of  37 

iron  in  sand  from 55 

National  Silica  Co., 

analysis  of  clay  from  quarry  of..  51 

-angularity  test  of  sand  from 151 

carbonaceous  bands  in  quarry  of.  37 

description  of  plant 80-84 

effective  size  of  sand  from 155 

fineness  tests  of  sand  from 148,  150 

flow  sheet  of 82 

iron  in  sand  from 55 

location  of  quarry  of 17,  63,  165 

sieve  analysis  of  sample  from ....  45 
uniformity     coefficient     of     sand 

from    155 

New  Richmond  sandstone 18,  19 

New  Richmond  sand  compared  with 

St.  Peter   28 

North  Bluff,  see  Illinois  River  Bluff 

North  Chicago,  St.  Peter  at 20 

Number  of  grains,  see  "Analyses" 


Octahedrite  in  St.  Peter 59,  60 

Ogle  Co.,  St.  Peter  in: 

eolian  ripple  marks  in 35 

outcrops  of   17,  166 

Oglesby,  St.  Peter  near 16 

Oolite,  in  Shakopee  formation 19 


172 


INDEX 


PAGE 

Oolitic  chert,  in  basal  St.  Peter.  ...       21 

Oregon : 

National  Silica  Co.  at 37 

St.  Peter  near 17,  49 

Oregon-Dixon  area : 

clay  content  of  St.  Peter  in 54 

formations  overlying  St.  Peter  in.        17 

outcrops  of  St.  Peter  in 14,  16,  166 

St.    Peter-Platteville   contact   in..       22 

Overburden,  removal  of 65-66 

See  also  "Plants,  description  of 

Ottawa,  St.  Peter  near  : 

clay  in    37 

commercial  development  of 12 

heavy  mineral  content  of .......  .       62 

potentially   valuable    162 

Ottawa  district : 
beds  removed  by  erosion  near ....       22 
"magnesia"  beds  in 50 

Ottawa  Silica  Co., 

analysis  of  sand  from. .  . 154 

angularity  test  of  sand  from 151 

description  of  Plants  A,  B 78 

effective  size  of  sand  from 155 

fineness  tests  of  sand  from. .  .  .148,  150 

sieve  analyses  of  sand  from 

....41,  42,  43,  44,  45,  152,  153,  154 

Ottawa  Silica  Molding  Sand  Co., 

description  of   plant 93 

fineness  tests  of  sand  from 148,150 

iron  in  sand  from 55 

Ottawa  Standard  Testing  sand 75 

production  in   1925 11 

See  also  "Testing  sand" 

Ottawa-Utica  district 

clay  content  of  St.  Peter  in 52 

clay    pockets    in 37 

iron  in  St.  Peter  in 57 

sand   quarries   in 77 

St.   Peter   in 14,44,45 

potentially  valuable  St.  Peter  in.162-163 

Oxvchloride  cement    109 


Paint  manufacture,  sand  for  use  in.      130 

Paleozoic   sandstones    27 

Parting  sand,  see  "Molding  sand" 


PAGE 

Pecumsaugan   Creek : 

St.   Peter  near 16 

Shakopee-St.  Peter  contact  along.  21 

potentially  valuable  St.  Peter  near  164 
Pennsylvanian  beds 

clay  content  in  area  overlain  by .  . 

52,53,54 

description  of 14,  16,  22 

Per  cent  of  fineness 156 

Pine  Creek,  St.  Peter  along 17 

Pit  quarries 63,  64 

Pitting  of   sand  grains 47-49 

Placing  sand,  see  "Saggar  sand" 

Plant-run  sample 144 

Plants,  description  of  : 
Producers  of  crude  sand : 

American  Silica  Sand  Co 86 

Bellrose  Sand  Co 87 

Benson- Richards    Sand   Co....  88 

Buffalo  Rock  Silica  Co 89 

Commonwealth  Silica  Co 90 

Federal  Silica  Mines 90 

Higby-Reynolds  Silica  Co 91 

Illinois  Valley  Silica  Co 92 

National  Plate  Glass  Co 93 

Ottawa  Silica  Molding  Sand  Co.  93 

Rock  Island  Silica  Sand  Co...  94 

South  Ottawa  Silica  Sand  Co.  .  95 

Standard  Silica  Co 95 

Utica  Fire  Sand  Co 96 

Wilkinson  Sand  Co 96 

Producers  of  washed  sand : 

Ballou  White  Sand  Co 76 

Higby-Reynolds   Silica  Co 78 

National  Silica  Co 80-84 

Ottawa  Silica  Co 78 

Standard  Silica  Co 79 

U.  S.  Silica  Co 80 

Wedron    Silica    Co 80 

Plasters,    sand    for 131 

Platteville-Galena  limestone, 

deposition  of   30 

described  in  geologic  section 22,  23 

overlying    St.    Peter 14,  17,  57,  65 

Pleistocene    period    31 

Plugging  oil  wells,  sand  for 132 

Polishing  sand,  see  "Grinding  sand" 
Potsdam    sandstone,    source    of    St. 

Peter   sand    26 


173 


PAGE 

Pottery,   sand   for   use   in   manufac- 
ture of    133 

Poultry  and  bird  grit 134 

Prairie  du  Chien  series,  surface  of.  19,  24 

Preliminary  screening    72 

Preparation  of  washed  sand 63-74 

Pre-St.   Peter  land  mass.  .....  .20,  27,  29 

Producers,    see   Plants,   descriptions 

of 
Production  of  silica  sand  in  1925.  .  .        11 

Purpose   of    report 12 

Pyrite  in  St.  Peter 56,  59,  60,  61 

See  also  "Iron  content" 

Q 

Quarries,   sand : 

located  on  map 77 

producing  washed  sand 63 

types  of    63 

See  also  "Plants,  descriptions  of" 
Quarrying : 

of  crude  sand 84 

of    St.    Peter   sand 63-68 

blasting     66 

hydraulic    67 

overburden  and  its  removal ....  65 
See  also  "Plants,  descriptions  of" 

Quincy,  St.  Peter  at 50 

R 

Railroad  ballast,  sand  as 134 

Railroad  fills,  sand  for 134 

Red  St.  Peter  sand,  iron  in 55 

Refractory    mortars     and    cements, 

sand  for   135 

Refractory  ware,  sand  for 135 

Relief  in  St.  Peter 25 

Residual  clays    20 

Ripple  marks  in  St.  Peter  : 

criteria  for  marine  origin  of ...  .  27-28 

discussion  of    33-35 

Rock    Island    Co.,    shale    below    St. 

Peter  in   20 

Rock  Island  Silica  Sand  Co., 

description  of   plant 94 

fineness  tests  on  sand  from.  .  .  .148,  150 

iron  in  sand   from 55 

Rock  River,  St.  Peter  along : 
outcrops  of   16,  17 


PAGE 

worm  borings  in 36 

Rock  terrace 

St.   Peter  in 14 

potentially  valuable  St.  Peter  in.  .  162 

Roofing  sand    135 

S 

Saggar   or  placing  sand 136 

St.  Peter  beds,  thickness  of 32 

St.  Peter-Glenwood  contact 24 

St.  Peter  sand,  compared  with : 

New  Richmond  sand 18,  28 

Shakopee  sand   29 

St.   Peter  sea 29 

St.   Peter  sandstone  : 

distribution  of    14-18 

geology  of 14-31 

iron  in   54-59 

lithology  of   18-24,  32-39 

origin  of    26 

tests  of,  see  "Analyses" 

thickness   of    24 

uses  of,  see  Chapter  5 

stratigraphic  relations  of 25 

structural  features  of  : 

bedding 32 

cross-bedding    32 

dessication  or  sun  cracks 36 

honeycomb   weathering    35 

ripple  marks   33 

worm  borings   36 

structure  of    25-26 

Samples : 
analyses  of,  see  "Analyses" 
descriptions    of,    sec    "Plants,    de- 
scriptions of" 

kinds  of   144 

Sampling  of  St.  Peter  sand 143-146 

"Sand"  and  "sandstone"  defined....        12 

Sandbags,    sand   for 136 

Sand  baths,  sand  for 137 

Sand-blast  sand   97,  136 

production   in    1925 11 

Sand  cement   109 

Sand-clay  roads   137 

Sand-finishing  painted  surfaces,  sand 

for   138 

Sand-finishing    plaster    walls,    sand 

for   138 


174 


PAGE 

Sand  grains  of  St.  Peter : 

frosting    46 

number  of   49 

pitting    47-49 

secondary   enlargment    49 

shape    44-46 

size   40-44 

St.  Peter  and  Shakopee  compared      19 

Sand  seals,  sand  for 138 

Sand  paper 138 

Sand  piles,  sand  for 138 

Sandstone,   commercial  development 

of  12 

potentially  valuable  deposits  of.  .162-166 
Sand  tables  and  sand  piles,  sand  for     139 

Savanna-Sabula  anticline    25 

Sawing  sand,  see  "Cutting  and  saw- 
ing sand" 

Screening  sand 72,  74 

Screens  : 

types  of    74 

used 147 

Scolithus  minnesotensis  Hall 36 

Scouring  sand    139 

Secondary     enlargement     of      sand 

grains    49 

Section,  geologic : 

from    quarry    of     Buffalo     Rock 

Silica  Co 89 

from    quarry    of    Illinois    Valley 

Silica  Co 92 

from  quarry  of   Benson-Richards 

Sand  Co • 88 

from    quarry    of     Ottawa    Silica 

Molding  Sand  Co 94 

from   quarry    of    Standard    Silica 

Co 95 

of    Glenwood    formation 22,  23 

of  Shakopee  formation  in  La  Salle 

area     19 

showing  iron-stained  bands  in  St. 

Peter     38 

Setting  sand   139 

Shakopee   limestone    19,20,21,29 

Shape  of  sand  grains 44-46 

"Sheety"  structure  in  St.    Peter....       33 

Shipping  sand    74 

Shirland,  St.  Peter  near 18,  35 

Sidewalks,   sand   for 139 


PAGE 

Sieve  analyses: 

constants   for    147 

demand  for   12 

of  Glenwood  sand 23 

See  also  "Analyses" 
Silica  mold  wash  for  foundry  use..     113 
Silica  or  sand  mold  wash,  See  "Fac- 
ing sand" 

Silica  sand  industry  in  1925 11 

Siliceous  joint  fillings 39 

Silicon,  sand  for  making 139 

Size  of  heavy"  mineral  grains  in  St. 

Peter 61 

Size  of  St.  Peter  sand  grains 40-44 

Standard  Silica  Co., 

angularity  test  of  sand  from 151 

clay  content  at  quarry  of 52 

description  of  Plants  1,  2 79 

description  of  Plant  3 95 

effective  size  and  uniformity  coef- 
ficient of  sand  from 155 

interstitial     organic     material     in 

quarry  of  37,  53 

iron  in  sand  from 55 

organic  material  in  quarry  of ... .  37-38 

sieve  analyses  of  sand  from 45 

Starved  Rock  State  Park 16,  164 

Standard  Ottawa  sand 75 

See  also  "Testing  sand" 
Stratigraphic  relations  of  St.  Peter.       25 

Structure  of  St.  Peter 25-26 

Steel  molding  sand 16 

production  in   1925 11 

See  also  "Molding  sand" 
Stone-block  pavements,  sand  f or . . .     140 

Stucco,  sand  for 140 

Soaps,  sand  for  use  in 140 

Sodium  silicate,  sand  for  making...     140 

Source  of  St.  Peter  sand 30 

South  Ottawa  Silica  Sand  Co., 

description  of  plant 95 

fineness  tests  of  sand  from 148,  150 

iron  in  sand  from 55 

sieve  analyses  of  sand  from 45 

Special  sand  products 74-76 

Spinel,  in  St.  Peter 59,60,61 

Split  Rock,  St.  Peter  near 16, 163 

Sugar  River: 

Glenwood  formation  along 23 

St.   Peter  along 18,  35 


175 


PAGE 

Sun  cracks  : 

in  "magnesia"  beds 38 

in  St.   Peter 28 

Sweeping  compounds,  sand  in 141 

Sycamore,  St.  Peter  at 24 

T 

Tar  and  roofing  paper,  sand  in 141 

Terrazzo  floors,  sand  for 141 

Testing  detonators,  sand  for 141 

Testing     sand :     Standard     Ottawa 

sand     141 

Testing  sand,  methods  of 146 

Tests  for  angularity 148-151 

Tests  to  determine  number  of  grains 

in  unit  weight  of  sand. . . 152-153 

Tests,  value  of 143 

Texture,  modes  of  expressing. ..  .155-158 

Texture  of  St.  Peter 42 

Thebes,   structure  near 25 

Thickness  of  St.  Peter 24 

Tomohawk  Creek,  St.  Peter  near . .       16 

Tourmaline,  in  St.  Peter 59,60,61 

Troy  Grove,  St.  Peter  near 16 

Tumbling  sand  141 

Twin  bluffs,  St.  Peter  near 14,  62 

Tyler  Standard  Screen  Scale  Sieves, 

constants   for    147 

U 

Uniformity  coefficient  of  sand 155 

United  States  Silica  Co., 

analyses  of  clay  from 51 

analyses  of  sand  from 154 

cross-bedding  in  quarry  of 32 

description  of  plant 80 

fineness  tests  of  sand  from 148,150 

effective  size  of  sand  from 155 

in,  Ottawa  terrace 63 

sieve  analyses  of  sand  from 45 

Uses    of    sand,    alphabetically   listed 

and  indexed  99-100 

Utica  Fire  Sand  Co., 

description  of  plant 96 

fineness  tests  on  sand  from. . .  .148,  150 
sieve  analyses  of  sand  from 45 

Utica-La  Salle  area 19 

Undeveloped  deposits  of  St.  Peter. 162-166 


PAGE 

Valmeyer  anticline   25 

Vermilion  River,  St.  Peter  along . .     164 


W 

Wall  plasters   131 

Washed  St.  Peter  sand,  flow  sheet 

for  68 

Washed  sand,  grades  produced : 

banding   sand    97 

glass  sand   97 

ground  silica  97 

mine-run  sand 97 

sand-blast  sand 97 

miscellaneous  grades    97 

washed  and  drained  sand 97 

Washed     sand,     producers     of,     see 
"Plants,  descriptions  of" 

Washing  sand   72-73 

Water  glass,   sand  for  making,  see 

"Sodium  silicate" 

Water  supplies  from  St.   Peter ....  25 

Waterloo  anticline,  effects  of 25 

Weathering,  effects  of  on  St.  Peter. 

18,19,25 

West  Point  Landing,  St.  Peter  near 

33,166 

Wedron  Silica  Co., 

analysis  of  sand  from 154 

angularity  test  of  sand  from 151 

description  of  plant 80 

fineness  tests  of  sand  from. . .  .148,  150 

iron  in  sand  from 55 

sieve  analyses  of  sand  from.  .41,  45, 153 

Whiteside  Co.,   St.  Peter  in 24 

Wilkinson  Sand  Co., 

description  of  plant 96 

Winnebago  Co., 

Glenwood  sand  in 23 

St.  Peter  in : 18,35 

Wood  block  pavements,  sand  for . . .  142 

Woodstock,  St.  Peter  at 24 

Worm  borings,  in  "magnesia"  beds.  38 

in  St.   Peter 28 

Z 

Zion  City,  St.  Peter  at 20 

Zircon,   in   St.    Peter 59,  60,  61 


